Positioning method and related device for unmanned aerial vehicle

Abstract

The present application discloses a method for mapping and positioning based on a drone and a related device. The method includes, during the flight of the drone, based on the positioning analysis module, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module, solving the posture data of the drone in the world coordinate system and outputting it through the odometer of the laser radar positioning module; after real-time fusion of the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module, the real-time posture data of the drone in the world coordinate system is obtained. The present application solves the technical problem of realizing effective positioning and mapping of drones when switching between indoors and outdoors. The present application realizes functions such as free switching between indoors and outdoors and indoor mapping and positioning.

Description

Technical Field

[0001] The present application relates to the field of drone positioning and mapping, and more specifically, to a positioning method and related devices for drones. Background Art

[0002] Drones, especially industrial drones, have developed rapidly in recent years. The application of industrial drones has evolved from the initial aerial survey and disaster relief to the current indoor firefighting, coal panning in coal plants, tunnel surveys, etc.

[0003] However, when the drone switches freely between indoors and outdoors and performs real-time mapping and positioning indoors, re-positioning will basically fail due to large changes in the environment.

[0004] With regard to the problem of effective positioning and mapping of drones when switching between indoor and outdoor environments in related technologies, no effective solution has been proposed so far. Summary of the invention

[0005] The main purpose of this application is to provide a positioning method and related devices for drones to solve the problem of effective positioning and mapping when the drone switches between indoors and outdoors.

[0006] In order to achieve the above objective, according to one aspect of the present application, a positioning method for a drone is provided.

[0007] The UAV includes: an IMU module, which is used to send the posture data of the UAV to the positioning and analysis module; a laser radar positioning module, which is used to scan the point cloud data and send it to the positioning and analysis module; an RTK positioning module, which is used to send the GPS positioning data and heading data to the positioning and analysis module, and receive the rtcm data of the RTK base station; a positioning and analysis module, which is used to receive the control instructions transmitted by the ground station and the rtcm data of the RTK base station; a data transmission module, which is used to send the map data parsed by the positioning and analysis module and the flight data of the UAV to the ground station; a flight control module, which is used to receive the first packaged data sent by the positioning and analysis module; the flight control module is also used to receive the second packaged data sent by the positioning and analysis module, and send a control instruction to the UAV, wherein the control instruction is determined according to the first packaged data and the second packaged data. The first packaged data and the second packaged data are different types of data; the method includes: during the flight of the UAV, based on the positioning analysis module, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module are solved to obtain the posture data of the UAV in the world coordinate system and output through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map based on the point cloud data; according to the origin position coordinates of the UAV in the world coordinate system, the GPS position and heading data obtained in the RTK positioning module are converted to the world coordinate system; the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module are integrated in real time to obtain the real-time posture data of the UAV in the world coordinate system.

[0008] Furthermore, it also includes: pre-mapping the indoor environment and obtaining partial area map data through the odometer of the laser radar positioning module; mapping the target area according to the positioning data and heading data obtained by the RTK positioning module when the drone is flying, as well as the partial area map data, to obtain all the target area map data.

[0009] Furthermore, during the flight of the UAV, the positioning analysis module calculates the posture data of the UAV in the world coordinate system based on the data obtained from the IMU module, the lidar positioning module, and the RTK positioning module, and outputs it through the odometer of the lidar positioning module, and also includes: the data obtained from the IMU is integrated in real time to calculate the posture data of the lidar positioning module; the lidar point cloud data caused by the motion distortion of the UAV is corrected according to the posture data; feature points are extracted and matched from the corrected lidar point cloud data; and the lidar map obtained after the feature points of all frames are matched is output through the odometer of the lidar positioning module.

[0010] Furthermore, after obtaining the laser radar map after matching the feature points of all frames output by the odometer of the laser radar positioning module, it also includes a step of improving the posture accuracy of the laser radar odometer output: roughly matching the laser odometer with the previous frame of laser point cloud data based on the next frame or multiple frames of new point laser point cloud data, and accurately matching with the laser radar map at the same time.

[0011] Furthermore, it also includes: through the positioning analysis module, the position and posture data are obtained in real time through a preset obstacle avoidance algorithm, and the UAV is guided to avoid obstacles on the flight path.

[0012] Furthermore, the method for optimizing the positioning accuracy of the RTK positioning module includes: when performing outdoor positioning of the UAV based on the RTK base station and the RTK mobile station, the position of the RTK base station antenna is fixed by stakes, and the coordinates of the current RTK base station antenna are recorded; the RTK base station is set up at the fixed position by stakes, and the coordinates of the RTK base station antenna are input into the RTK base station when establishing the map.

[0013] Furthermore, the method for optimizing the positioning accuracy of the RTK positioning module includes: determining the system position information of the RTK base station antenna based on a third-party positioning system, and acquiring the system position information through the third-party positioning system when establishing a map.

[0014] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a positioning device for a drone is provided, and the drone includes: an IMU module, used to send the attitude data of the drone to the positioning and analysis module; a laser radar positioning module, used to scan the point cloud data and send it to the positioning and analysis module; an RTK positioning module, used to send the GPS positioning data and heading data to the positioning and analysis module, and receive the rtcm data of the RTK base station; a positioning and analysis module, used to receive the control instructions transmitted by the ground station and the rtcm data of the RTK base station; a data transmission module, used to send the map data parsed by the positioning and analysis module and the flight data of the drone to the ground station; a flight control module, used to receive the first packaged data sent by the positioning and analysis module; the flight control module is also used to receive the second packaged data sent by the positioning and analysis module, and send control instructions to the drone, wherein the control instructions are based on the first packaged data and the second packaged data. The data determines that the first packaged data and the second packaged data are different types of data; the device includes: a mapping module, which is used to solve the posture data of the drone in the world coordinate system based on the positioning analysis module for the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module during the flight of the drone, and output it through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map based on point cloud data; a coordinate conversion module, which is used to convert the GPS position and heading data obtained in the RTK positioning module into the world coordinate system according to the origin position coordinates of the drone in the world coordinate system; a fusion positioning module, which is used to obtain the real-time posture data of the drone in the world coordinate system after real-time fusion of the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module.

[0015] Furthermore, the device also includes: a pre-mapping module, which pre-maps the indoor environment and obtains partial area map data through the odometer of the lidar positioning module; a full map building module, which is used to map the target area according to the positioning data and heading data obtained by the RTK positioning module when the drone is flying, as well as the partial area map data, so as to obtain all the target area map data.

[0016] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a UAV is provided, comprising: an IMU module, used to send the attitude data of the UAV to the positioning and analysis module; a lidar positioning module, used to scan the point cloud data and send it to the positioning and analysis module; an RTK positioning module, used to send the GPS positioning data and heading data to the positioning and analysis module, and receive the RTCM data of the RTK base station; a positioning and analysis module, used to receive the control instructions transmitted by the ground station and the RTCM data of the RTK base station; a data transmission module, used to send the map data obtained by the positioning and analysis module and the flight data of the UAV to the ground station; a flight control module, used to receive the first packaged data sent by the positioning and analysis module; the flight control module is also used to receive the second packaged data sent by the positioning and analysis module, and send control instructions to the UAV, wherein the control instructions are determined according to the first packaged data and the second packaged data, and the first packaged data and the second packaged data are different types of data.

[0017] In the positioning method and related device for unmanned aerial vehicles in the embodiment of the present application, during the flight of the unmanned aerial vehicle, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module are solved based on the positioning analysis module to solve the posture data of the unmanned aerial vehicle in the world coordinate system and output through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map according to the point cloud data; according to the origin position coordinates of the unmanned aerial vehicle in the world coordinate system, the GPS position and heading data obtained in the RTK positioning module are converted to the world coordinate system; after the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module are fused in real time, the posture data of the unmanned aerial vehicle in real time in the world coordinate system is obtained. Thus, the technical effect that the unmanned aerial vehicle can be accurately positioned when the environment changes is achieved, thereby solving the technical problem of effectively positioning and mapping the unmanned aerial vehicle when switching between indoor and outdoor. In addition, the present application can also display the laser radar map in the target area in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0019] Figure 1 is a schematic diagram of the hardware structure implemented in the positioning method for a drone according to an embodiment of the present application;

[0020] Figure 2 is a schematic flow chart of a positioning method for a drone according to an embodiment of the present application;

[0021] Figure 3 is a structural schematic diagram of a positioning device for a drone according to an embodiment of the present application;

[0022] Figure 4 is a schematic diagram of the working principle between airborne modules in the positioning method for a drone according to an embodiment of the present application;

[0023] Figure 5 It is a schematic diagram of the process of real-time mapping and position calculation of a drone in a positioning method for a drone according to an embodiment of the present application;

[0024] Figure 6 is a schematic diagram of free switching between outdoor and indoor locations in a positioning method for a drone according to an embodiment of the present application;

[0025] Figure 7 is a schematic diagram of the structure of a drone in a method for positioning a drone according to an embodiment of the present application;

[0026] Figure 8 It is a schematic diagram of the structure of a ground station in a positioning method for a drone according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0030] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0031] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] The inventors found that the difficulties of indoor drones mainly focus on the perception of the environment and the real-time mapping of the existing environment. On the basis of the mapping, real-time positioning is achieved, and the positioning data is used by the drone. At the same time, if the drone needs to repeat the indoor task, it also involves the repositioning of the map. However, there is currently no complete solution that perfectly solves the problem of drones switching freely between indoors and outdoors and real-time mapping and positioning indoors. Most repositioning requirements are very high, and it is necessary to compare the point cloud collected by the drone with the previous mapping point cloud. If the environment changes significantly, the repositioning will basically fail.

[0033] Based on the above, this application provides a drone positioning system and a drone-based mapping and positioning method to solve the real-time mapping and positioning from outdoor to indoor. By carrying two positioning systems on the drone, one RTK positioning and orientation system, the initial position and heading of the drone are provided by the RTK positioning system, and the other lidar positioning system, indoor mapping and positioning are achieved. The map created by the lidar on the drone will be sent to the ground station in real time through the fast transmission module. The ground station operator can see the indoor scene on the ground according to the real-time returned map. At the same time, the operator can set the guide position of the drone on the map to guide the drone to fly. Save the created map, and the next time you start the drone, load the saved map, set the guide points on the map, and after the aircraft takes off, it will automatically execute all the guide points.

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] like Figure 1 As shown, the hardware structure of the method for mapping and positioning based on drones of the present application includes: drones 100 and ground stations 200. Among them, the drones 100 include multiple drones, which can be industrial drones or consumer drones, which are not limited in the present application. The ground station 200 may include one or more. The ground station 200 cooperates with the drone 100 to achieve free switching between indoors and outdoors and real-time mapping and positioning indoors. The drone 100 is equipped with two positioning systems, one RTK positioning and orientation system, the initial position and heading of the drone are provided by the RTK positioning system, and the other laser radar positioning system, to achieve indoor mapping and positioning. The map established by the laser radar on the drone will be sent to the ground station in real time through the fast transmission module. The ground station operator can see the indoor scene on the ground according to the real-time returned map. At the same time, the operator can set the guidance position of the drone on the map to guide the drone to fly. Save the established map, load the saved map after starting the drone next time, set the guidance point on the map, and all the guidance points will be automatically executed after the aircraft takes off.

[0036] like Figure 2 as well as Figure 7 As shown, the drone comprises:

[0037] An IMU module is used to send the attitude data of the UAV to the positioning analysis module;

[0038] A laser radar positioning module, used for scanning point cloud data and sending it to the positioning analysis module;

[0039] RTK positioning module, used to send GPS positioning data and heading data to the positioning analysis module, and receive rtcm data from the RTK base station;

[0040] A positioning analysis module is used to receive control instructions transmitted by a ground station and rtcm data from the RTK base station;

[0041] A data transmission module, used for sending the map data obtained by the positioning analysis module and the flight data of the UAV to a ground station;

[0042] A flight control module, used for receiving the first packaged data sent by the positioning and analysis module;

[0043] The flight control module is further used to receive the second packaged data sent by the positioning and analysis module, and send a control instruction to the UAV, wherein the control instruction is determined according to the first packaged data and the second packaged data, and the first packaged data and the second packaged data are different types of data;

[0044] The method includes the following steps S201 to S204:

[0045] Step S201, during the flight of the UAV, the position data of the UAV in the world coordinate system is calculated based on the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module by the positioning analysis module, and the odometer output of the laser radar positioning module is used; wherein the odometer output is also used to generate a laser radar map according to the point cloud data;

[0046] Step S202, converting the GPS position and heading data acquired in the RTK positioning module into the world coordinate system according to the origin position coordinates of the UAV in the world coordinate system;

[0047] Step S203, after real-time fusion of the pre-integrated position in the IMU module, the posture data in the lidar positioning module, and the GPS position and heading data in the RTK positioning module, the real-time posture data of the UAV in the world coordinate system is obtained.

[0048] From the above description, it can be seen that the present application achieves the following technical effects:

[0049] During the flight of the drone, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module are solved based on the positioning analysis module to calculate the posture data of the drone in the world coordinate system and output through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map based on point cloud data; according to the origin position coordinates of the drone in the world coordinate system, the GPS position and heading data obtained in the RTK positioning module are converted to the world coordinate system; after the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module are fused in real time, the posture data of the drone in real time in the world coordinate system is obtained. Thus, the technical effect that the drone can accurately locate when the environment changes is achieved, thereby solving the technical problem of effectively positioning and mapping the drone when switching between indoor and outdoor. In addition, the present application can also display the laser radar map in the target area in real time.

[0050] The described UAV includes: an IMU module, a laser radar positioning module, an RTK positioning module, a positioning analysis module, a data transmission module, and a flight control module. The ground station transmits the command and the rtcm data of the RTK base station to the positioning and analysis module through the data transmission module, and the positioning and analysis module sends the map data and the data related to the UAV to the ground station through the data transmission module; the point cloud data scanned by the laser radar is sent to the positioning and analysis module through the network port, and the IMU module sends the attitude data to the positioning and analysis module through the USB; the RTK mobile station module sends the GPS positioning data and heading data to the positioning and analysis module through the serial port, and the positioning and analysis module transmits the rtcm data transmitted by the ground station to the RTK mobile station module through the serial port; there are two serial ports connected between the positioning and analysis module and the flight control module, and the high-performance positioning and solving module uses the data of the IMU, the data of the RTK, and the data of the laser radar to build a map and solve the position in real time, and sends the position and heading data to the flight control module through one of the serial ports, which is named the positioning data communication serial port; the positioning and solving module communicates with the flight control module through the second serial port, and sends control command information to the aircraft at the same time, which is named the control data communication serial port.

[0051] In the above step S201, during the flight of the drone, the positioning analysis module analyzes the relevant data obtained by the IMU module, the laser radar positioning module, and the RTK positioning module to calculate the current posture data of the drone in the world coordinate system. At the same time, the posture data is output through the odometer of the laser radar positioning module, and the laser radar map generated according to the point cloud data collected by the laser radar positioning module is also output on the odometer.

[0052] As an optional implementation of this embodiment, the odometer also outputs a laser radar map generated based on the point cloud data collected by the laser radar positioning module, which is visualized for users of the ground station. In the above step S202, the GPS position and heading data obtained by the RTK positioning module are converted into the world coordinate system according to the origin position coordinates of the current drone in the world coordinate system.

[0053] As an optional implementation of this embodiment, the positioning analysis module will integrate the laser radar odometer coordinate system and the GPS satellite positioning coordinate system in the RTK positioning module. The result of the integration is that the laser radar odometer coordinate system is synchronized to the GPS global coordinate system (world coordinate system). In other words, even if there is no GPS signal indoors, the drone can determine the current coordinates relative to the GPS coordinate system.

[0054] In the above step S203, based on the EKF posture solution, the posture data in the lidar positioning module, the GPS position and heading data in the RTK positioning module are integrated in real time by the pre-integrated position in the IMU module, and then the real-time posture data of the UAV in the world coordinate system is output, that is, the positioning position information of the UAV is determined.

[0055] As a preferred embodiment of this embodiment, it also includes: pre-mapping the indoor environment and obtaining partial area map data through the odometer of the laser radar positioning module; mapping the target area according to the positioning data and heading data obtained by the RTK positioning module when the drone is flying, as well as the partial area map data, to obtain all the target area map data.

[0056] In specific implementation, when mapping, the entire map is not built at the beginning. Instead, the indoor map is first mapped in advance through the odometer of the laser radar positioning module and partial area map data is obtained. Secondly, the target area is mapped based on the positioning data and heading data obtained by the RTK positioning module when the drone is flying, as well as the partial area map data, to obtain the entire target area map data.

[0057] It should be noted that in relatively open areas outdoors, due to the large error in the laser odometer's posture data, RTK positioning and orientation data is basically used as the main source of drone position solution outdoors. When the drone enters indoors, the RTK positioning and orientation will lose lock. At this time, the laser radar's position data accuracy is very high. Indoors, the laser radar odometer's posture data is basically used as the main source of drone position solution.

[0058] As a preferred embodiment of the present invention, during the flight of the UAV, the data obtained from the IMU module, the lidar positioning module, and the RTK positioning module are solved by the positioning analysis module to obtain the posture data of the UAV in the world coordinate system and output through the odometer of the lidar positioning module, and also include: the data obtained from the IMU is integrated in real time to calculate the posture data of the lidar positioning module; the lidar point cloud data caused by the motion distortion of the UAV is corrected according to the posture data; feature points are extracted and matched from the corrected lidar point cloud data; and the lidar map obtained after the feature points of all frames are matched is output through the odometer of the lidar positioning module.

[0059] During specific implementation, the data acquired from the IMU is integrated in real time to solve the attitude data of the laser radar positioning module, and the laser radar point cloud data caused by the motion distortion of the drone (motion distortion caused by the non-uniform motion of the drone) is further corrected according to the attitude data. Afterwards, feature points are extracted and matched from the corrected laser radar point cloud data. The matching of feature points mainly includes extracting angular features, line features and surface features according to the curvature of the point cloud, and aligning according to the angular features, line features and surface features of the previous frame of point cloud. Finally, the odometer of the laser radar positioning module outputs the laser radar map obtained after matching the feature points of all frames.

[0060] As a preferred embodiment of the present embodiment, after obtaining the laser radar map after matching the feature points of all frames output by the odometer of the laser radar positioning module, it also includes a step of improving the posture accuracy of the laser radar odometer output: roughly matching the laser odometer with the previous frame of laser point cloud data based on the next frame or multiple frames of new point laser point cloud data, and accurately matching with the laser radar map at the same time.

[0061] In specific implementation, a rough match of the laser odometer is performed based on the next frame or multiple frames of new laser point cloud data and the previous frame of laser point cloud data, thereby improving the position and posture accuracy of the laser radar odometer output.

[0062] As a preferred embodiment of this embodiment, it also includes: through the positioning analysis module, the position and posture data are obtained in real time through a preset obstacle avoidance algorithm, and the UAV is guided to avoid obstacles on the flight path.

[0063] In specific implementation, the set obstacle avoidance algorithm (3D-VFH) is used to solve and guide the path of the drone in real time to automatically avoid obstacles.

[0064] As a preferred embodiment of the present invention, the method for optimizing the positioning accuracy of the RTK positioning module includes: when performing outdoor positioning of the UAV based on the RTK base station and the RTK mobile station, the position of the RTK base station antenna is fixed by stakes, and the coordinates of the current RTK base station antenna are recorded; the RTK base station is set up at the fixed position by stakes, and the coordinates of the RTK base station antenna are input to the RTK base station when establishing the map.

[0065] In specific implementation, since the GPS coordinate accuracy of a single point is about 3m, this accuracy cannot meet the positioning requirements of outdoor and indoor drones, so it is necessary to improve the positioning accuracy of GPS. The drone uses the mode of RTK base station combined with RTK mobile station, and the positioning accuracy is within 10cm. If there is no need to save the map for future flights, the positioning accuracy of the system can be met. If you need to save the map for the next flight, you can fix the position of the RTK base station antenna by stake, and record the coordinates of the current base station antenna. The next time you fly again using the map, you need to set up the base station at the staked location, and input the coordinates of the base station when building the map into the RTK base station, so that the accuracy of the saved map can be guaranteed.

[0066] As a preference in this embodiment, the method for optimizing the positioning accuracy of the RTK positioning module includes: determining the system position information of the RTK base station antenna based on a third-party positioning system, and obtaining the system position information through the third-party positioning system when establishing a map.

[0067] During the specific implementation, in order to improve the positioning accuracy of GPS, based on the global positioning coordinate system provided by the third-party system, when the first map is constructed and the base station is set up, the rtcm data is obtained through the 4G module and the third-party system account; then, based on the absolute position of the base station antenna, it can be guaranteed that the map will be loaded again in the future. When the base station is set up, it is also necessary to obtain the absolute position of the base station antenna through Qianxun. The base station antenna can be set up arbitrarily and does not need to be fixed with piles.

[0068] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0069] According to an embodiment of the present application, a positioning device for a drone for implementing the above method is also provided, such as Figure 3 As shown Figure 7 The drone comprises:

[0070] An IMU module is used to send the attitude data of the UAV to the positioning analysis module;

[0071] A laser radar positioning module, used for scanning point cloud data and sending it to the positioning analysis module;

[0072] RTK positioning module, used to send GPS positioning data and heading data to the positioning analysis module, and receive rtcm data from the RTK base station;

[0073] A positioning analysis module is used to receive control instructions transmitted by a ground station and rtcm data from the RTK base station;

[0074] A data transmission module, used for sending the map data obtained by the positioning analysis module and the flight data of the UAV to a ground station;

[0075] A flight control module, used for receiving the first packaged data sent by the positioning and analysis module;

[0076] The flight control module is further used to receive the second packaged data sent by the positioning and analysis module, and send a control instruction to the UAV, wherein the control instruction is determined according to the first packaged data and the second packaged data, and the first packaged data and the second packaged data are different types of data;

[0077] The device includes:

[0078] A mapping module 301 is used to calculate the posture data of the UAV in the world coordinate system based on the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module by the positioning analysis module during the flight of the UAV, and output the posture data through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map according to the point cloud data;

[0079] A coordinate conversion module 302 is used to convert the GPS position and heading data obtained in the RTK positioning module into the world coordinate system according to the origin position coordinates of the UAV in the world coordinate system;

[0080] The fusion positioning module 303 is used to obtain the real-time posture data of the UAV in the world coordinate system by fusing the pre-integrated position in the IMU module, the posture data in the lidar positioning module, and the GPS position and heading data in the RTK positioning module in real time.

[0081] In the mapping module 301 of the embodiment of the present application, during the flight of the drone, the positioning analysis module analyzes the relevant data obtained by the IMU module, the laser radar positioning module, and the RTK positioning module to calculate the current drone's posture data in the world coordinate system. At the same time, the posture data is output through the odometer of the laser radar positioning module, and the odometer also outputs the laser radar map generated based on the point cloud data collected by the laser radar positioning module.

[0082] As an optional implementation of this embodiment, a laser radar map generated based on the point cloud data collected by the laser radar positioning module is also output on the odometer and is visualized for users of the ground station.

[0083] The coordinate conversion module 302 in the embodiment of the present application will convert the GPS position and heading data obtained by the RTK positioning module into the world coordinate system according to the origin position coordinates of the current drone in the world coordinate system.

[0084] As an optional implementation of this embodiment, the positioning analysis module will integrate the laser radar odometer coordinate system and the GPS satellite positioning coordinate system in the RTK positioning module. The result of the integration is that the laser radar odometer coordinate system is synchronized to the GPS global coordinate system (world coordinate system). In other words, even if there is no GPS signal indoors, the drone can determine the current coordinates relative to the GPS coordinate system.

[0085] In the fusion positioning module 303 in the embodiment of the present application, based on EKF posture solution, the pre-integrated position in the IMU module, the posture data in the lidar positioning module, and the GPS position and heading data in the RTK positioning module are fused in real time, and then the posture data of the drone in real time in the world coordinate system is output, that is, the positioning position information of the drone is determined.

[0086] As a preferred embodiment of this invention, it also includes:

[0087] A pre-mapping module 304 is used to pre-map the interior of the room and obtain map data of a part of the area through the odometer of the laser radar positioning module;

[0088] The full map building module 305 is used to build a map of the target area according to the positioning data and heading data obtained by the RTK positioning module when the UAV is flying, and the map data of the partial area, so as to obtain the map data of the entire target area.

[0089] In specific implementation, when mapping, the entire map is not built at the beginning. Instead, the indoor map is first mapped in advance through the odometer of the laser radar positioning module and partial area map data is obtained. Secondly, the target area is mapped based on the positioning data and heading data obtained by the RTK positioning module when the drone is flying, as well as the partial area map data, to obtain the entire target area map data.

[0090] It should be noted that in relatively open areas outdoors, due to the large error in the laser odometer's posture data, RTK positioning and orientation data is basically used as the main source of drone position solution outdoors. When the drone enters indoors, the RTK positioning and orientation will lose lock. At this time, the laser radar's position data accuracy is very high. Indoors, the laser radar odometer's posture data is basically used as the main source of drone position solution.

[0091] Obviously, those skilled in the art should understand that the above modules or steps of the present application can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, and optionally, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. In this way, the present application is not limited to any specific combination of hardware and software.

[0092] In order to better understand the process of the above-mentioned drone-based mapping and positioning method, the above-mentioned technical solution is explained below in combination with the preferred embodiment, but it is not used to limit the technical solution of the embodiment of the present application.

[0093] The preferred embodiment of the present application can realize the free switching of the drone between indoor and outdoor and real-time mapping and positioning indoors. Specifically, two positioning systems are installed on the drone, one is an RTK positioning and orientation system, the initial position and heading of the drone are provided by the RTK positioning system, and the other is a laser radar positioning system, so as to realize indoor mapping and positioning.

[0094] like Figure 4 , which is a schematic diagram of the working principles between airborne modules in the drone-based mapping and positioning method in an embodiment of the present application.

[0095] Figure 7It is a schematic diagram of the structure of a drone in the drone-based mapping and positioning method according to an embodiment of the present application. The drone includes: a lidar positioning module 101, a high-performance positioning solution module 102, an RTK positioning module 103, a high-precision IMU module 104, a data transmission module 105, an RTK main antenna 106, an RTK slave antenna 107, and a flight control module (not shown).

[0096] Figure 8 The ground station structure diagram of the UAV-based mapping and positioning method according to the embodiment of the present application includes: a ground station display screen 201, a ground station industrial computer 202, an RTK base station module 203, a ground station data transmission module 204, a 4G module 205, and an RTK base station antenna 206.

[0097] The embodiment of the present application also provides a drone 100 including:

[0098] An IMU module is used to send the attitude data of the UAV to the positioning analysis module;

[0099] A laser radar positioning module, used for scanning point cloud data and sending it to the positioning analysis module;

[0100] RTK positioning module, used to send GPS positioning data and heading data to the positioning analysis module, and receive rtcm data from the RTK base station;

[0101] A positioning analysis module is used to receive control instructions transmitted by a ground station and rtcm data from the RTK base station;

[0102] A data transmission module, used for sending the map data obtained by the positioning analysis module and the flight data of the UAV to a ground station;

[0103] A flight control module, used for receiving the first packaged data sent by the positioning and analysis module;

[0104] The flight control module is also used to receive the second packaged data sent by the positioning and analysis module, and send a control instruction to the UAV, wherein the control instruction is determined according to the first packaged data and the second packaged data, and the first packaged data and the second packaged data are different types of data.

[0105] Figure 5 The present invention is a flowchart of real-time drone mapping and position calculation in a drone-based mapping and positioning method according to an embodiment of the present application, which specifically includes the following steps:

[0106] Step S501, switch to the laser radar positioning module.

[0107] Step S502: point cloud motion distortion processing.

[0108] Step S503: point cloud feature extraction.

[0109] Step S504, using a laser radar odometer.

[0110] Step S505, generating a laser radar map.

[0111] Step S506, laser radar posture calculation.

[0112] In the above steps, the high-performance positioning solution module solves the posture of the drone in the XYZ coordinate system based on the point cloud data of the laser radar, the position and heading data of the RTK, and the high-precision IMU data. The IMU data solves the posture of the laser radar in real time through integration, and the laser radar point cloud data corrects the motion distortion caused by the non-uniform motion of the drone through the posture data solved by the IMU. After the point cloud data is corrected, feature points are extracted from the point cloud data. The angular features, line features, and surface features are extracted mainly based on the curvature of the point cloud. The registration is performed based on the angular features, line features, and surface features of the previous frame of the point cloud to realize the laser odometer and output the posture and position data in real time. After matching the key features of all frames, a laser radar map is formed. After a few frames of new point cloud data arrive, after a rough match of the laser odometer with the previous frame, it is necessary to accurately match it with the laser radar map to improve the posture accuracy output by the laser radar odometer.

[0113] Step S507, IMU integrated posture.

[0114] Step S508, RTK position data and RTK heading data.

[0115] Step S509, XYZ world coordinates.

[0116] Step S510, EKF pose solution.

[0117] In the above steps, after the RTK position and heading data are obtained, the GPS position and heading data need to be converted to the XYZ coordinate system according to the take-off point of the drone (the origin of the XYZ coordinate system). Finally, the EKF pose solution integrates the pre-integrated position of the IMU, the positioning and heading data of the RTK, and the pose data of the lidar in real time to obtain the current pose data of the drone in the XYZ coordinate system. In relatively open areas outdoors, due to the large error in the pose data of the laser odometer, RTK positioning and orientation data is basically used as the main source of drone position solution outdoors. When the drone enters indoors, the RTK positioning and orientation will lose lock. At this time, the position data accuracy of the lidar is very high, and the pose data of the lidar odometer is basically used as the main source of drone position solution indoors.

[0118] Figure 6It is a schematic diagram of free switching between outdoor and indoor in the drone-based mapping and positioning method according to an embodiment of the present application.

[0119] Taking the outdoor as the outdoors and the indoor as the factory as an example, the free switching between the outdoor and indoor in the mapping and positioning method is specifically implemented in the following way:

[0120] like Figure 6 The figure shows a drone taking off from the outdoors, being guided by the ground station into the indoors, and then flying indoors under the guidance of the ground station. The circle and the number in it represent a guide point, the ellipse and the letter in it represent an obstacle, and the dotted line represents the actual path of the drone executing the ground station. The coordinate system of this system is a right-hand regular coordinate system with X forward, Y left, and Z upward. Y points to the north direction (270°), and the origin of the coordinate system is defined as the first take-off point before the map is established. The coordinates of this point are (0,0,0), which is the guide point No. 1 in the figure (solid circle).

[0121] Since the 1 (solid circle) and 2 guide points are outdoors, the positioning of the high-performance positioning module is provided by GPS data. The GPS coordinates of point 1 (solid circle) are used as reference points. The coordinates of this point in the XYZ coordinate system are (0,0,0). All GPS position data received by the high-performance positioning module outdoors are converted to the XYZ coordinate system. All position calculations are completed in the high-performance positioning calculation module.

[0122] Before loading the built map, after the drone is started, the drone will build a map based on GPS data and laser radar data, and transmit the built map to the ground station in real time. The operator can then set the guide point on the map. After the aircraft is unlocked, the ground station switches the aircraft to the guidance mode, sends the aircraft the guide point 1, guides the drone to take off, and after the drone hovers over the guide point 1, the ground operator sets the guide point 2 on the map. Since there are no obstacles between the guide points 1 and 2, the drone flies from the guide point 1 to the guide point 2 in a straight line.

[0123] At the No. 2 guide point, the laser radar has begun to map the room, and the ground station will soon show part of the indoor map. When the indoor map is displayed on the ground, the ground station operator sets the No. 3 guide point. During the flight from No. 2 to No. 3 guide point, the RTK state will be lost. At this time, the high-performance positioning solution module will switch the heading and positioning data to the positioning data of the laser radar real-time mapping and positioning, and the coordinate system still belongs to the XYZ coordinate system.

[0124] When the drone hovers at the No. 3 guide point, the indoor map is basically established, and the ground station operator can guide the drone to the No. 4, 5, and 6 guide points in turn. Since there is an obstacle A between the No. 4 and 5 guide points, the high-performance positioning solution module will use the set obstacle avoidance algorithm (3D-VFH) to solve and guide the drone's path in real time and automatically avoid obstacles.

[0125] When the drone is hovering at the guide point 6, the ground station operator can continue to set the guide point 3->2->1 to guide the drone back to the take-off point, and then switch the drone to land mode and land on the ground under GPS positioning. Secondly, the ground station operator can also send a return message to the drone, and the high-precision positioning solution module will calculate the optimal path to avoid obstacles and return. The ground station operator sends a command to the drone through the ground station to save the current map and name the map "factory map".

[0126] When the map is built, take off again, and the drone is placed at point 1 in the dotted circle. The ground station operator can load the "factory map" in the drone through the ground station command, and the factory map will be transmitted back to the ground station. At this time, the ground station has a complete map of the first map. The drone will calculate the coordinates of the current aircraft in the XYZ coordinate system based on the GPS coordinates corresponding to the origin of the map's XYZ coordinate system and the GPS coordinates of the current aircraft. After the map is available, the ground station operator can set the guidance points he needs. After the setting is completed, unlock the drone and switch to the guidance mode. After the drone takes off, it hovers above the guidance point No. 1 (dashed circle), checks the subsequent guidance points, and guides the flight in sequence. After the guidance points are flown, wait for the next command from the ground station operator.

[0127] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A positioning method for a drone, characterized in that: The drone comprises: An IMU module is used to send the attitude data of the drone to a positioning analysis module; A laser radar positioning module, used for scanning point cloud data and sending it to the positioning analysis module; RTK positioning module, used to send GPS positioning data and heading data to the positioning analysis module, and receive rtcm data from the RTK base station; The positioning analysis module is used to receive the control instructions transmitted by the ground station and the rtcm data of the RTK base station; A data transmission module, used for sending the map data obtained by the positioning analysis module and the flight data of the UAV to a ground station; A flight control module, used for receiving the first packaged data sent by the positioning and analysis module; The flight control module is further used to receive the second packaged data sent by the positioning and analysis module, and send a control instruction to the UAV, wherein the control instruction is determined according to the first packaged data and the second packaged data, and the first packaged data and the second packaged data are different types of data; The method comprises: During the flight of the UAV, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module are solved by the positioning analysis module to calculate the posture data of the UAV in the world coordinate system and output it through the odometer of the laser radar positioning module; wherein the odometer output is also used to generate a laser radar map according to the point cloud data; According to the origin position coordinates of the UAV in the world coordinate system, the GPS position and heading data acquired in the RTK positioning module are converted into the world coordinate system; After real-time fusion of the pre-integrated position in the IMU module, the posture data in the laser radar positioning module, and the GPS position and heading data in the RTK positioning module, the real-time posture data of the UAV in the world coordinate system is obtained; Also includes: Pre-map the interior and obtain partial area map data using the odometer of the laser radar positioning module; According to the positioning data and heading data obtained by the RTK positioning module when the UAV is flying, and the map data of the partial area, the target area is mapped to obtain the map data of the entire target area. During the flight of the UAV, the data obtained from the IMU module, the laser radar positioning module, and the RTK positioning module are solved by the positioning analysis module to calculate the posture data of the UAV in the world coordinate system and output it through the odometer of the laser radar positioning module, including: The data obtained from the IMU is integrated to calculate the attitude data of the laser radar positioning module in real time; Correcting the laser radar point cloud data caused by the motion distortion of the drone according to the posture data; Extract and match feature points from the corrected LiDAR point cloud data; The laser radar map obtained after the feature points of all frames are matched is output by the odometer of the laser radar positioning module, and the laser radar map obtained after the feature points of all frames are matched is output by the odometer of the laser radar positioning module, and the step of improving the posture accuracy output by the laser radar odometer is also included: According to the next frame or multiple frames of new laser point cloud data, a rough match is performed with the laser odometer of the previous frame of laser point cloud data, and an accurate match is performed with the laser radar map at the same time; Also includes: Through the positioning analysis module, the position and posture data are calculated in real time through a preset obstacle avoidance algorithm, and the UAV is guided to avoid obstacles on the flight path.

Images