Unmanned aerial vehicle and mobile platform speed synchronization control method, flight control system and unmanned aerial vehicle

Abstract

The invention relates to the technical field of unmanned aerial vehicle control, in particular to a speed synchronization control method of an unmanned aerial vehicle and a mobile platform, a flight control system and the unmanned aerial vehicle, and the speed synchronization control method comprises the steps: obtaining GNSS information, visual beacon information or mobile visual positioning information according to the relative distance between the unmanned aerial vehicle and the mobile platform, and performing real-time control on the unmanned aerial vehicle by using the acquired GNSS information, the visual beacon information or the mobile visual positioning information so as to realize speed synchronization between the unmanned aerial vehicle and the mobile platform. According to the invention, through mutual complementation and assistance of multiple speed synchronization modes, the optimal speed synchronization mode can be automatically selected for different distance ranges, accurate speed synchronization between the unmanned aerial vehicle and the mobile platform in a complex environment is realized, and accurate following or accurate landing between the unmanned aerial vehicle and the mobile platform can be realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of unmanned aerial vehicle (UAV) control, and particularly to a method for speed synchronization control between a UAV and a mobile platform, a flight control system, and a UAV. Background Art

[0002] With the continuous development of UAV technology, UAVs have been widely used in multiple fields such as agriculture, surveying and mapping, power inspection, and disaster relief. When performing tasks, UAVs often need to dock with mobile platforms such as vehicles and ships, which requires the UAVs to maintain the same speed and motion trajectory as the mobile platforms in order to accurately follow and land. However, in the prior art, there are certain difficulties in speed synchronization between UAVs and mobile platforms, the synchronization accuracy and stability need to be improved, and there is a lack of flexible adaptability for different scenarios.

[0003] Currently, the speed synchronization between UAVs and mobile platforms mainly relies on GPS positioning or is achieved through technologies such as image matching. However, these methods have defects such as low reliability and low efficiency in practical applications, and require operators to have rich experience to flexibly control the UAVs for synchronization. Therefore, how to achieve precise speed synchronization between UAVs and mobile platforms using a simple program has become an urgent problem to be solved. Summary of the Invention

[0004] To solve the problems in the related art, embodiments of the present disclosure provide a method for speed synchronization control between a UAV and a mobile platform, a flight control system, and a UAV.

[0005] In a first aspect, embodiments of the present disclosure provide a method for speed synchronization control between a UAV and a mobile platform, including: The UAV receives a speed synchronization control instruction sent by a remote controller, and approaches the mobile platform in the horizontal direction under the control of the remote controller, where the remote controller is disposed on the mobile platform; When the horizontal relative distance between the UAV and the mobile platform is greater than or equal to a first set threshold, the UAV obtains GNSS information in real time, and performs real-time control according to the obtained GNSS information to achieve speed synchronization with the mobile platform; When the horizontal relative distance is less than the first set threshold and greater than a second set threshold, the UAV obtains visual beacon information in real time, and performs real-time control according to the obtained visual beacon information to achieve speed synchronization with the mobile platform; When the mobile platform is within the visual perception range of the UAV and the horizontal relative distance is less than the second set threshold until the UAV is directly above the mobile platform, the UAV obtains real-time mobile visual positioning information by identifying the feature markers on the mobile platform, and performs real-time control according to the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0006] According to an embodiment of the present disclosure, the method further includes: when the horizontal relative distance is equal to the second set threshold, the UAV approaches the mobile platform in the height direction under the control of the remote controller so that the mobile platform is within the visual perception range of the UAV.

[0007] According to an embodiment of the present disclosure, the method further includes: While the UAV obtains visual beacon information in real time, the UAV obtains GNSS information of the mobile platform in real time; compares the deviation between the GNSS information and the visual beacon information obtained at the same moment; when the deviation is greater than or equal to the third set threshold, filters the GNSS information and the visual beacon information obtained at the same moment to obtain fusion control information; The UAV performs real-time control according to the fusion control information to achieve speed synchronization with the mobile platform.

[0008] According to an embodiment of the present disclosure, the method further includes: After the UAV is directly above the mobile platform, the UAV receives a landing instruction and lands on the landing area of the mobile platform according to the landing instruction.

[0009] According to an embodiment of the present disclosure, the GNSS information includes: the GNSS vector speed and GNSS position of the mobile platform, and the GNSS position of the UAV; The real-time control according to the obtained GNSS information to achieve speed synchronization with the mobile platform includes: calculating a first speed according to the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV, and generating a first speed control instruction according to the first speed to control the UAV to achieve speed synchronization with the mobile platform.

[0010] According to an embodiment of the present disclosure, the calculation of the first speed according to the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV is achieved through the following formula: ; ; ; wherein, is the first speed, is the first proportionality coefficient, is the first speed feedforward coefficient, is the real-time speed of the mobile platform, is the initial position difference vector between the UAV and the mobile platform, is the real-time position difference vector between the UAV and the mobile platform, is the initial position vector of the UAV, is the initial position vector of the mobile platform, is the real-time position vector of the UAV, is the real-time position vector of the mobile platform.

[0011] According to an embodiment of the present disclosure, the visual beacon information includes the visual beacon position and visual beacon speed of the mobile platform in the video transmission screen of the UAV, and the visual beacon position of the UAV; The real-time control according to the acquired visual beacon information to achieve speed synchronization with the mobile platform includes: calculating a second speed according to the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV, and generating a second speed control instruction according to the second speed to control the UAV to achieve speed synchronization with the mobile platform.

[0012] According to an embodiment of the present disclosure, the calculation of the second speed according to the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV is achieved through the following formula: ; ; ; wherein, is the second speed, is the second proportionality coefficient, is the second speed feedforward coefficient, is the real-time visual beacon speed of the mobile platform, is the initial visual beacon position difference vector between the mobile platform and the UAV, is the real-time visual beacon position difference vector between the mobile platform and the UAV, is the initial visual beacon position vector of the UAV, is the initial visual beacon position vector of the mobile platform, is the real-time visual beacon position vector of the UAV, is the real-time visual beacon position vector of the mobile platform.

[0013] According to an embodiment of the present disclosure, the mobile visual positioning information includes the visual positioning position and speed of the mobile platform in the drone video transmission screen, and the visual positioning position of the drone. The real-time control according to the mobile visual positioning information to achieve speed synchronization with the mobile platform includes: Calculating a third speed based on the visual positioning position and speed of the mobile platform and the visual positioning position of the drone, and generating a third speed control instruction according to the third speed to control the drone to achieve speed synchronization with the mobile platform.

[0014] According to an embodiment of the present disclosure, the calculation of the third speed based on the visual positioning position and speed of the mobile platform and the visual positioning position of the drone is achieved through the following formula: ; ; ; where is the third speed, is the third proportionality coefficient, is the third speed feedforward coefficient, is the real-time visual positioning speed of the mobile platform, is the initial visual positioning position difference vector between the mobile platform and the drone, is the real-time visual positioning position difference vector between the mobile platform and the drone, is the initial visual positioning position vector of the drone, is the initial visual positioning position vector of the mobile platform, is the real-time visual positioning position vector of the drone, is the real-time visual positioning position vector of the mobile platform.

[0015] In a second aspect, an embodiment of the present disclosure provides a flight control system, which is arranged on a drone and includes: A receiving module, configured to receive a speed synchronization control instruction sent by a remote controller, and approach a mobile platform in the horizontal direction under the control of the remote controller, where the remote controller is arranged on the mobile platform. The first speed synchronization module is configured to, when the horizontal relative distance between the drone and the mobile platform is greater than or equal to a first set threshold, the drone acquires GNSS information in real time and performs real-time control according to the acquired GNSS information to achieve speed synchronization with the mobile platform; The second speed synchronization module is configured to, when the horizontal relative distance is less than the first set threshold and greater than a second set threshold, the drone acquires visual beacon information in real time and performs real-time control according to the acquired visual beacon information to achieve speed synchronization with the mobile platform; The third speed synchronization module is configured to, when the mobile platform is within the visual perception range of the drone and the horizontal relative distance is less than the second set threshold until the drone is directly above the mobile platform, the drone acquires mobile visual positioning information in real time by identifying the feature markers on the mobile platform and performs real-time control according to the acquired mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0016] According to an embodiment of the present disclosure, the system further includes: a height adjustment module; The height adjustment module is configured to, when the horizontal relative distance is equal to the second set threshold, control the drone to approach the mobile platform in the height direction until the mobile platform is within the visual perception range of the drone.

[0017] According to an embodiment of the present disclosure, the system further includes a fourth speed synchronization module; The fourth speed synchronization module is configured to, while the drone acquires visual beacon information in real time, the drone acquires the GNSS information of the mobile platform in real time; compare the deviation between the GNSS information and the visual beacon information acquired at the same moment; when the deviation is greater than or equal to a third set threshold, filter the GNSS information and the visual beacon information acquired at the same moment to obtain fusion control information; the drone performs real-time control according to the fusion control information to achieve speed synchronization with the mobile platform.

[0018] According to an embodiment of the present disclosure, the system further includes a landing module; The landing module is configured to, after the drone is directly above the mobile platform, the drone receives a landing instruction and lands on the landing area of the mobile platform according to the landing instruction.

[0019] In a third aspect, an embodiment of the present disclosure provides a drone, including the flight control system according to any one of the second aspect.

[0020] According to the technical solution provided by the embodiments of the present disclosure, the unmanned aerial vehicle (UAV) receives a speed synchronization control instruction sent by a remote controller disposed on a mobile platform, and approaches the mobile platform in the horizontal direction under the control of the remote controller; when the horizontal relative distance between the UAV and the mobile platform is greater than or equal to a first set threshold, the UAV obtains GNSS information in real time, when the horizontal relative distance is less than the first set threshold and greater than or equal to a second set threshold, the UAV obtains visual beacon information in real time, when the mobile platform is within the visual perception range of the UAV and the horizontal relative distance is less than the second set threshold until the UAV is directly above the mobile platform, the UAV obtains mobile visual positioning information in real time, so as to perform real-time control on the UAV according to the obtained GNSS information, visual beacon information or mobile visual positioning information when the horizontal relative distance meets different set threshold ranges, so as to achieve speed synchronization with the mobile platform.

[0021] The present disclosure can automatically select the optimal speed synchronization method for different distance ranges in the face of complex and changeable operation scenarios, realize accurate speed synchronization between the UAV and the mobile platform in a complex environment, enable the UAV to achieve accurate following or accurate landing with the mobile platform, significantly reduce the dependence on the experience of operators, effectively overcome the deficiencies of using a single synchronization method, improve the accuracy and flexibility of speed synchronization, and can be widely applied to multiple fields such as agriculture, surveying and mapping, power inspection, and disaster relief.

[0022] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In combination with the drawings, through the following detailed description of non-limiting embodiments, other features, objects and advantages of the present disclosure will become more obvious. In the drawings: Figure 1 Show a flowchart of a method for controlling speed synchronization between a UAV and a mobile platform according to an embodiment of the present disclosure; Figure 2 Show a schematic diagram of an application scenario of a method for controlling speed synchronization between a UAV and a mobile platform when the horizontal relative distance is greater than or equal to a first set threshold in an embodiment of the present disclosure; Figure 3 Show a schematic diagram of an application scenario of a method for controlling speed synchronization between a UAV and a mobile platform when the horizontal relative distance is less than a first set threshold and greater than a second set threshold in an embodiment of the present disclosure; Figure 4 Show a schematic diagram of an application scenario of a method for controlling speed synchronization between a UAV and a mobile platform when the horizontal relative distance is less than a second set threshold until the UAV is directly above the mobile platform in an embodiment of the present disclosure; Figure 5 The structural block diagram of a flight control system according to an embodiment of the present disclosure is shown. Detailed implementation manners

[0024] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. In addition, for clarity, parts irrelevant to the description of the exemplary embodiments are omitted in the drawings.

[0025] In the present disclosure, it should be understood that terms such as "including" or "having" are intended to indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof disclosed in this specification, and are not intended to exclude the possibility of the presence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] In addition, it should be noted that, without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other. Hereinafter, the present disclosure will be described in detail with reference to the drawings and in combination with the embodiments.

[0027] In the present disclosure, if it involves operations of obtaining user information or user data or presenting user information or user data to others, such operations are all operations authorized, confirmed by the user, or actively selected by the user.

[0028] As mentioned above, in the prior art, the speed synchronization between the unmanned aerial vehicle and the mobile platform mainly relies on GPS positioning or is achieved through technologies such as image matching. However, these methods have defects such as low reliability and low efficiency in actual applications, and require operators to have rich experience to flexibly control the unmanned aerial vehicle for synchronization. Therefore, how to achieve precise speed synchronization between the unmanned aerial vehicle and the mobile platform using a simple program has become an urgent problem to be solved.

[0029] In the present disclosure, a drone receives a speed synchronization control instruction sent by a remote controller disposed on a mobile platform, and approaches the mobile platform horizontally under the control of the remote controller; when the horizontal relative distance between the drone and the mobile platform is greater than or equal to a first set threshold, the drone acquires GNSS information in real time, and performs real-time control according to the acquired GNSS information to achieve speed synchronization with the mobile platform; when the horizontal relative distance is less than the first set threshold and greater than or equal to a second set threshold, the drone acquires visual beacon information in real time, and performs real-time control according to the acquired visual beacon information to achieve speed synchronization with the mobile platform; when the mobile platform is within the visual perception range of the drone, and the horizontal relative distance is less than the second set threshold until the drone is directly above the mobile platform, the drone acquires mobile visual positioning information in real time by recognizing a feature marker on the mobile platform, and performs real-time control according to the acquired mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0030] The present disclosure can automatically select the optimal speed synchronization method for different distance ranges, and achieve precise speed synchronization between the drone and the mobile platform in a complex environment, so that the drone can achieve precise following or precise landing with the mobile platform.

[0031] Figure 1 The flowchart of the speed synchronization control method for a drone and a mobile platform according to an embodiment of the present disclosure is shown. As Figure 1 shown, the speed synchronization control method includes the following steps S101 to S104: In step S101, the drone receives a speed synchronization control instruction sent by the remote controller, and approaches the mobile platform horizontally under the control of the remote controller, where the remote controller is disposed on the mobile platform.

[0032] Among them, the remote controller is the core device for the user to interact with the drone, and transmits operation instructions to the drone through wireless communication technology. The mobile platform, as the carrier of the remote controller, can be an automobile, a mobile ground station, a ship, etc. The form of the remote controller disposed on the mobile platform can be various. For example, the driver on the mobile platform can hold the remote controller, or the remote controller can be directly fixedly disposed on the mobile platform.

[0033] In the present disclosure, when the user wants to enable speed synchronization, the user can send a speed synchronization instruction to the drone through the remote controller. After receiving the speed synchronization instruction, the drone continuously approaches the mobile platform horizontally under the control of the remote controller, and performs real-time speed synchronization control during the approaching process.

[0034] In step S102, when the horizontal relative distance between the drone and the mobile platform is greater than or equal to a first set threshold, the drone acquires GNSS information in real time and performs real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform.

[0035] The inventors noticed that the mobile platform is a key device that provides necessary support and cooperation for the takeoff, landing, and various related operations of the drone during the ground stage. When the drone successfully takes off and enters the flight state, according to the spatial layout logic of the two, the mobile platform is naturally located below the drone.

[0036] Based on this spatial position relationship, the technical solution of the present disclosure simplifies the operation. Specifically, when dealing with motion planning, position positioning, and cooperative control related to the drone and the mobile platform within a set distance range, there is no need to consider the height vector, and only the horizontal relative distance needs to be considered. This simplified processing can not only reduce the computational complexity, improve the response speed and operation efficiency of the system, but also reduce the errors that may be caused by considering too many variables to a certain extent, thereby providing a more reliable and efficient solution for the speed synchronization control of the drone and the mobile platform.

[0037] In the present disclosure, the first set threshold can be customized. For example, it can be 50 meters, 60 meters, and so on.

[0038] Specifically, the GNSS information includes: the GNSS vector speed and GNSS position of the mobile platform, and the GNSS position of the drone.

[0039] According to an embodiment of the present disclosure, the real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform includes: calculating a first speed based on the GNSS vector speed and GNSS position of the mobile platform, and the GNSS position of the drone, and generating a first speed control command based on the first speed to control the drone to achieve speed synchronization with the mobile platform.

[0040] Specifically, the first speed can be calculated according to a first proportionality coefficient, a first speed feedforward coefficient, the real-time speed of the mobile platform, the initial position difference vector and real-time position difference vector between the drone and the mobile platform, the initial position vector and real-time position vector of the drone, and the initial position vector and real-time position vector of the mobile platform.

[0041] Among them, the first proportionality coefficient is the proportionality coefficient used when calculating the first speed. In the scenario of controlling the speed of an unmanned aerial vehicle (UAV), it is necessary to generate a control quantity based on the deviation (i.e., speed error) between the speed of the UAV at the current moment and the speed of the mobile platform. The proportionality coefficient determines the linear relationship between this control quantity and the speed error.

[0042] The first speed feedforward coefficient is the speed feedforward coefficient used when calculating the first speed. During the process of the UAV following the mobile platform, it is necessary to directly generate a feedforward control quantity based on the set speed of the mobile platform. The speed feedforward coefficient is a parameter used to adjust the relationship between this feedforward control quantity and the set speed.

[0043] The first proportionality coefficient and the first speed feedforward coefficient can be set according to experience. For example, they can be set to fixed values or adaptively. For example, the first proportionality coefficient is 3 - 5, and the first speed feedforward coefficient is 0 - 1, which can be set according to needs. Those skilled in the art should understand that the set values of the first proportionality coefficient and the first speed feedforward coefficient are not technical means for limiting the protection scope of this disclosure.

[0044] Furthermore, calculating the first speed based on the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV is achieved through the following formula: ; ; ; Among them, is the first speed, is the first proportionality coefficient, is the first speed feedforward coefficient, is the real - time speed of the mobile platform, is the initial position difference vector between the UAV and the mobile platform, is the real - time position difference vector between the UAV and the mobile platform, is the initial position vector of the UAV, is the initial position vector of the mobile platform, is the real - time position vector of the UAV, is the real - time position vector of the mobile platform.

[0045] In this disclosure, since there is no need to consider the height vector during the process of achieving speed synchronization within the set distance range, the variables used within the set distance range are all two - dimensional variables. That is, all variables in the above formula for calculating the first speed are two - dimensional variables.

[0046] Since the first speed is calculated when the horizontal relative distance between the UAV and the mobile platform is greater than or equal to a first set threshold, the initial position difference vector between the UAV and the mobile platform and the real-time position difference vector are both greater than or equal to the first set threshold.

[0047] Suppose , , then item B can ensure the tracking real-time performance between the UAV and the mobile platform, and item A corrects item B, reducing the speed control error and ensuring that the relative distance between the UAV and the mobile platform remains unchanged or within a certain range.

[0048] Figure 2 Fig. shows an application scenario schematic diagram of the speed synchronization control method between the UAV and the mobile platform when the horizontal relative distance is greater than or equal to the first set threshold in the embodiments of the present disclosure.

[0049] In Figure 2 In a specific embodiment shown, the pilot of the UAV is on the mobile platform, receives the GNSS vector speed and GNSS position of the mobile platform through the remote controller, and transmits them to the UAV; the UAV calculates the first speed according to the GNSS vector speed and GNSS position of the mobile platform obtained through the remote controller, and combines the GNSS position of the UAV measured by itself, and generates a first speed control instruction accordingly to control the speed synchronization between the UAV and the mobile platform. Through the speed synchronization of the two, the relative synchronous movement between the UAV and the mobile platform can be realized, that is, the speeds are the same and the relative position remains within a certain range, or the horizontal movement trajectory of the UAV can be parallel to the movement trajectory of the mobile platform.

[0050] In addition, the pilot can adjust the relative position between the UAV and the mobile platform through the joystick of the remote controller. When the pilot operates the joystick, the initial position difference vector between the UAV and the mobile platform is correspondingly changed. At this time, the initial position difference vector after releasing the joystick is used as the new initial position difference vector to regenerate the first speed to continue to maintain the speed synchronization between the UAV and the mobile platform.

[0051] In step S103, when the horizontal relative distance is less than the first set threshold and greater than the second set threshold, the UAV obtains the visual beacon information in real time, and performs real-time control according to the obtained visual beacon information to achieve speed synchronization with the mobile platform.

[0052] According to the embodiments of the present disclosure, the visual beacon information includes the visual beacon position and visual beacon speed of the mobile platform in the UAV video transmission screen, and the visual beacon position of the UAV.

[0053] In the present disclosure, the video transmission screen of the unmanned aerial vehicle (UAV) refers to the image or video data captured in real time by the UAV through a video transmission system and transmitted to a receiving device (such as the screen of a remote controller, a mobile phone, a tablet computer, etc.), enabling the operator to view the content of the image captured by the UAV in real time. The visual beacon position refers to the spatial coordinate vector of the target detected by the UAV through visual sensors (such as a camera, a depth camera) in the video transmission screen of the UAV. The visual beacon speed refers to the motion speed vector of the target in the video transmission screen of the UAV, that is, the visual beacon information belongs to the coordinates in the video transmission coordinate system and is a two-dimensional variable.

[0054] According to an embodiment of the present disclosure, the real-time control based on the acquired visual beacon information to achieve speed synchronization with the mobile platform includes: calculating a second speed based on the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV, and generating a second speed control instruction based on the second speed to control the UAV to achieve speed synchronization with the mobile platform.

[0055] Specifically, the second speed can be calculated according to a second proportionality coefficient, a second speed feedforward coefficient, the real-time visual beacon speed of the mobile platform, the initial visual beacon position difference vector and the real-time visual beacon position difference vector between the mobile platform and the UAV, the initial visual beacon position vector and the real-time visual beacon position vector of the UAV, and the initial visual beacon position vector and the real-time visual beacon position vector of the mobile platform.

[0056] Similarly, the second proportionality coefficient and the second speed feedforward coefficient can be set according to experience, for example, they can be set as fixed values or adaptively set.

[0057] Further, the calculation of the second speed based on the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV is achieved through the following formula: ; ; ; where is the second speed, is the second proportionality coefficient, is the second speed feedforward coefficient, is the real-time visual beacon speed of the mobile platform, is the initial visual beacon position difference vector between the mobile platform and the UAV, is the visual beacon position difference vector between the mobile platform and the UAV, is the initial visual beacon position vector of the UAV, is the initial visual beacon position vector of the mobile platform, is the real-time visual beacon position vector of the UAV, is the real-time visual beacon position vector of the mobile platform.

[0058] Since the second speed is calculated when the horizontal relative distance between the UAV and the mobile platform is less than the first set threshold and greater than the second set threshold, the initial position difference vector and the real-time position difference vector between the UAV and the mobile platform are both less than the first set threshold and greater than the second set threshold.

[0059] Figure 3 shows a schematic diagram of the application scenario of the speed synchronization control method between the UAV and the mobile platform when the horizontal relative distance is less than the first set threshold and greater than the second set threshold in the embodiments of the present disclosure.

[0060] In Figure 3 In a specific implementation shown, the UAV collects images of the mobile platform through an image transmission camera. The user frames and marks the mobile platform in the image transmission screen of the UAV. The UAV locks the mobile platform as the target, obtains the visual beacon position and visual beacon speed of the mobile platform, and combines its own visual beacon position to calculate the second speed, and accordingly generates a second speed control instruction to control the speed synchronization between the UAV and the mobile platform, and realizes the relative synchronous movement between the UAV and the mobile platform through the speed synchronization of the two.

[0061] Similarly, the driver can also adjust the relative position between the UAV and the mobile platform through the joystick of the remote controller to re-determine the new initial visual beacon position difference vector, so as to re-generate the second speed to continue to maintain the speed synchronization between the UAV and the mobile platform.

[0062] In the present disclosure, the second set threshold can be set as needed, and the second set threshold is less than the first set threshold. Assuming that the first set threshold is 30 meters, the second set threshold can be 5 meters, 1 meter, 0.5 meters, and so on.

[0063] The inventor found that when using GNSS information for speed control, although the determined speed is relatively accurate, it may produce jumps, thus affecting the use experience of the UAV during actual control, such as jitter. When using visual beacon information for speed control, the determined speed is relatively smooth, but the accuracy will be slightly reduced. If GNSS information and visual beacon information can be comprehensively considered, then the finally determined speed can improve the jitter of the UAV while ensuring the accuracy of speed synchronization control.

[0064] According to an embodiment of the present disclosure, while the drone obtains visual beacon information in real time, the drone obtains GNSS information of the mobile platform in real time; compares the deviation between the GNSS information and the visual beacon information obtained at the same moment; when the deviation is greater than or equal to a third set threshold, filters the GNSS information and the visual beacon information obtained at the same moment to obtain fusion control information; and the drone performs real-time control according to the fusion control information to achieve speed synchronization with the mobile platform.

[0065] Among them, the filtering may be Kalman filtering, particle filtering, complementary filtering, etc., but is not limited thereto, as long as it can achieve filtering of the GNSS information and the visual beacon information.

[0066] In step S104, when the mobile platform is within the visual perception range of the drone and the horizontal relative distance is less than or equal to the second set threshold until the drone is directly above the mobile platform, the drone obtains mobile visual positioning information in real time by identifying feature markers on the mobile platform, and performs real-time control according to the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0067] In the present disclosure, a landing area is provided on the mobile platform. The drone being directly above the mobile platform can be understood as that the relative distance in the horizontal direction between the drone and the edge of the landing area has a very small deviation or is zero, or the relative distance in the horizontal direction between the drone and the center point of the landing area has a very small deviation or is zero.

[0068] According to an embodiment of the present disclosure, when the horizontal relative distance is equal to the second set threshold, the drone approaches the mobile platform in the height direction under the control of the remote controller so that the mobile platform is within the visual perception range of the drone.

[0069] Among them, the visual perception range refers to the range within which the drone can effectively identify and perceive the mobile platform through its visual sensor (such as a camera). Within this range, the drone can capture sufficient visual information to locate / navigate the mobile platform.

[0070] According to an embodiment of the present disclosure, the mobile visual positioning information includes the visual positioning position and visual positioning speed of the mobile platform in the drone's video transmission screen, and the visual positioning position of the drone.

[0071] In the present disclosure, when obtaining mobile vision positioning information, the drone not only transmits the original images captured by the camera, but also identifies the feature markers on the mobile platform through an image processing algorithm, and determines the vision positioning position and speed of the mobile platform. These information are then superimposed on the original images to form an enhanced video transmission screen integrated with vision positioning information.

[0072] According to an embodiment of the present disclosure, the real-time control according to the mobile vision positioning information to achieve speed synchronization with the mobile platform includes: calculating a third speed according to the vision positioning position and vision positioning speed of the mobile platform and the vision positioning position of the drone, and generating a third speed control instruction according to the third speed to control the drone to achieve speed synchronization with the mobile platform.

[0073] Specifically, the third speed can be calculated according to a third proportionality coefficient, a third speed feedforward coefficient, the real-time vision positioning speed of the mobile platform, the initial vision positioning position difference vector and the real-time vision positioning position difference vector between the mobile platform and the drone, the initial vision positioning position vector and the real-time vision positioning position vector of the drone, and the initial vision positioning position vector and the real-time vision positioning position vector of the mobile platform.

[0074] Similarly, the third proportionality coefficient and the third speed feedforward coefficient can be custom-set according to actual needs.

[0075] Further, the calculation of the third speed according to the vision positioning position and vision positioning speed of the mobile platform and the vision positioning position of the drone is achieved through the following formula: ; ; ; where is the third speed, is the third proportionality coefficient, is the third speed feedforward coefficient, is the real-time vision positioning speed of the mobile platform, is the initial vision positioning position difference vector between the mobile platform and the drone, is the real-time vision positioning position difference vector between the mobile platform and the drone, is the initial vision positioning position vector of the drone, is the initial vision positioning position vector of the mobile platform, is the real-time vision positioning position vector of the drone, is the real-time vision positioning position vector of the mobile platform.

[0076] It is known that the initial visual positioning position difference vector between the mobile platform and the UAV needs to satisfy being less than or equal to a second set threshold until it becomes zero. Therefore, the initial visual positioning position difference vector between the mobile platform and the UAV and the real-time visual positioning position difference vector between the mobile platform and the UAV need to be less than or equal to the second set threshold until it becomes 0. When the initial visual positioning position difference vector is zero, the UAV is located directly above the mobile platform. At this time .

[0077] Figure 4 FIG. shows an application scenario schematic diagram of the speed synchronization control method between the UAV and the mobile platform when the horizontal relative distance is less than the second set threshold until the UAV is located directly above the mobile platform in an embodiment of the present disclosure.

[0078] In Figure 4 In a specific implementation shown, the UAV acquires feature markers on the mobile platform through a visual sensor, identifies the feature markers on the mobile platform through an image processing algorithm, determines the visual positioning position and visual positioning speed of the mobile platform, combines its own visual positioning position vector, calculates a third speed, and generates a third speed control instruction accordingly to control the speed synchronization between the UAV and the mobile platform, so that the UAV can maintain above the mobile platform.

[0079] According to an embodiment of the present disclosure, after the UAV is located directly above the mobile platform, the UAV receives a landing instruction and lands in the landing area of the mobile platform according to the landing instruction.

[0080] The present disclosure can be directed to complex and changeable operation scenarios, integrates multiple speed synchronization methods, can automatically select the optimal speed synchronization method for different distance ranges, so as to achieve accurate speed synchronization between the UAV and the mobile platform in a complex environment, enabling the UAV to achieve precise following or precise landing with the mobile platform, significantly reducing the dependence on the experience of operators, effectively overcoming the deficiencies of using a single speed synchronization method, and improving the accuracy and flexibility of speed synchronization.

[0081] Figure 5 FIG. shows a structural block diagram of a flight control system 500 according to an embodiment of the present disclosure.

[0082] The flight control system is provided on the UAV. As Figure 5 shown, the flight control system 500 includes a receiving module 510, a first speed synchronization module 520, a second speed synchronization module 530, and a third speed synchronization module 540.

[0083] The receiving module 510 is configured to receive a speed synchronization control instruction sent by a remote controller, and approach the mobile platform in the horizontal direction under the control of the remote controller, wherein the remote controller is disposed on the mobile platform.

[0084] The first speed synchronization module 520 is configured to, when the horizontal relative distance between the drone and the mobile platform is greater than or equal to a first set threshold, the drone obtains GNSS information in real time and performs real-time control according to the obtained GNSS information to achieve speed synchronization with the mobile platform.

[0085] The second speed synchronization module 530 is configured to, when the horizontal relative distance is less than the first set threshold and greater than a second set threshold, the drone obtains visual beacon information in real time and performs real-time control according to the obtained visual beacon information to achieve speed synchronization with the mobile platform.

[0086] The third speed synchronization module 540 is configured to, when the mobile platform is within the visual perception range of the drone and the horizontal relative distance is less than the second set threshold until the drone is directly above the mobile platform, the drone obtains mobile visual positioning information by recognizing feature markers on the mobile platform and performs real-time control according to the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0087] According to an embodiment of the present disclosure, the system further includes: a height adjustment module configured to, when the horizontal relative distance is equal to the second set threshold, control the drone to approach the mobile platform in the height direction until the mobile platform is within the visual perception range of the drone.

[0088] According to an embodiment of the present disclosure, the system further includes: a fourth speed synchronization module configured to, while the drone obtains visual beacon information in real time, the drone obtains GNSS information of the mobile platform in real time; compare the deviation between the GNSS information and the visual beacon information obtained at the same moment; when the deviation is greater than or equal to a third set threshold, filter the GNSS information and the visual beacon information obtained at the same moment to obtain fusion control information; and the drone performs real-time control according to the fusion control information to achieve speed synchronization with the mobile platform.

[0089] According to an embodiment of the present disclosure, the system further includes: the landing module configured to, after the drone is directly above the mobile platform, the drone receives a landing instruction and lands on the landing area of the mobile platform according to the landing instruction.

[0090] The present disclosure also discloses a drone, which includes the flight control system as described in any of the previous embodiments.

[0091] Through the flight control system, the drone realizes speed synchronization control with the mobile platform.

[0092] The units or modules involved in the embodiments described in the present disclosure can be implemented in software or by programmable hardware. The described units or modules can also be set in a processor, and the names of these units or modules do not constitute a limitation on the units or modules themselves in some cases.

[0093] The above description is only a preferred embodiment of the present disclosure and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solution formed by the specific combination of the above technical features, but also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the (but not limited to) technical features with similar functions disclosed in the present disclosure.

Claims

1. A method for speed synchronization control of an unmanned aerial vehicle and a mobile platform, characterized in that, Including: The drone receives a speed synchronization control instruction sent by the remote controller and approaches the mobile platform in the horizontal direction under the control of the remote controller, where the remote controller is set on the mobile platform; When the horizontal relative distance between the drone and the mobile platform is greater than or equal to a first set threshold, the drone acquires GNSS information in real time and performs real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform; When the horizontal relative distance is less than the first set threshold and greater than a second set threshold, the drone acquires visual beacon information in real time and performs real-time control based on the acquired visual beacon information to achieve speed synchronization with the mobile platform; When the mobile platform is within the visual perception range of the drone and the horizontal relative distance is less than or equal to the second set threshold until the drone is directly above the mobile platform, the drone acquires mobile visual positioning information in real time by recognizing feature markers on the mobile platform and performs real-time control based on the acquired mobile visual positioning information to achieve speed synchronization with the mobile platform.

2. The method according to claim 1, wherein The method further includes: when the horizontal relative distance is equal to the second set threshold, the drone approaches the mobile platform in the height direction under the control of the remote controller so that the mobile platform is within the visual perception range of the drone.

3. The method according to claim 1, wherein The method further includes: While the drone acquires visual beacon information in real time, the drone acquires the GNSS information of the mobile platform in real time; compares the deviation between the GNSS information and the visual beacon information acquired at the same moment; when the deviation is greater than or equal to a third set threshold, filters the GNSS information and the visual beacon information acquired at the same moment to obtain fusion control information; The drone performs real-time control based on the fusion control information to achieve speed synchronization with the mobile platform.

4. The method according to claim 1, wherein The method further includes: After the drone is directly above the mobile platform, the drone receives a landing instruction and lands on the landing area of the mobile platform according to the landing instruction.

5. The method according to claim 1, wherein: The GNSS information includes: the GNSS vector speed and GNSS position of the mobile platform, and the GNSS position of the drone; The performing real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform includes: calculating a first speed based on the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the drone, and generating a first speed control instruction based on the first speed to control the drone to achieve speed synchronization with the mobile platform.

6. The method according to claim 5, wherein The calculating the first speed based on the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the drone is achieved by the following formula: ； ； ； Wherein, is the first speed, is the first proportionality coefficient, is the first speed feedforward coefficient, is the real-time speed of the mobile platform, is the initial position difference vector between the drone and the mobile platform, is the real-time position difference vector between the drone and the mobile platform, is the initial position vector of the drone, is the initial position vector of the mobile platform, is the real-time position vector of the drone, is the real-time position vector of the mobile platform.

7. The method according to claim 1, wherein: The visual beacon information includes the visual beacon position and visual beacon speed of the mobile platform in the video transmission screen of the UAV, and the visual beacon position of the UAV; The real-time control according to the acquired visual beacon information to achieve speed synchronization with the mobile platform includes: calculating a second speed based on the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV, and generating a second speed control command according to the second speed to control the UAV to achieve speed synchronization with the mobile platform.

8. The method according to claim 7, characterized in that The calculation of the second speed based on the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV is achieved through the following formula: ； ； ； Wherein, is the second speed, is the second proportionality coefficient, is the second speed feedforward coefficient, is the real-time visual beacon speed of the mobile platform, is the initial visual beacon position difference vector between the mobile platform and the UAV, is the real-time visual beacon position difference vector between the mobile platform and the UAV, is the initial visual beacon position vector of the UAV, is the initial visual beacon position vector of the mobile platform, is the real-time visual beacon position vector of the UAV, is the real-time visual beacon position vector of the mobile platform.

9. The method according to claim 1, wherein: The mobile visual positioning information includes the visual positioning position and visual positioning speed of the mobile platform in the video transmission screen of the UAV, and the visual positioning position of the UAV; The real-time control according to the mobile visual positioning information to achieve speed synchronization with the mobile platform includes: Calculating a third speed based on the visual positioning position, visual positioning speed of the mobile platform, and the visual positioning position of the UAV, and generating a third speed control command according to the third speed to control the UAV to achieve speed synchronization with the mobile platform.

10. The method according to claim 9, characterized in that, The calculation of the third speed based on the visual positioning position, visual positioning speed of the mobile platform, and the visual positioning position of the UAV is achieved through the following formula: ； ； ； Among them, is the third speed, is the third proportionality coefficient, is the third speed feedforward coefficient, is the real-time visual positioning speed of the mobile platform, is the initial visual positioning position difference vector between the mobile platform and the drone, is the real-time visual positioning position difference vector between the mobile platform and the drone, is the initial visual positioning position vector of the drone, is the initial visual positioning position vector of the mobile platform, is the real-time visual positioning position vector of the drone, is the real-time visual positioning position vector of the mobile platform.

11. A flight control system, characterized in that, The flight control system is arranged on the UAV and includes: A receiving module, configured to receive a speed synchronization control command sent by a remote controller, and approach the mobile platform in the horizontal direction under the control of the remote controller, wherein the remote controller is arranged on the mobile platform; A first speed synchronization module, configured to, when the horizontal relative distance between the UAV and the mobile platform is greater than or equal to a first set threshold, the UAV acquires GNSS information in real time and performs real-time control according to the acquired GNSS information to achieve speed synchronization with the mobile platform; A second speed synchronization module, configured to, when the horizontal relative distance is less than the first set threshold and greater than a second set threshold, the UAV acquires visual beacon information in real time and performs real-time control according to the acquired visual beacon information to achieve speed synchronization with the mobile platform; A third speed synchronization module, configured to, when the mobile platform is within the visual perception range of the UAV and the horizontal relative distance is less than the second set threshold until the UAV is directly above the mobile platform, the UAV acquires mobile visual positioning information in real time by identifying feature markers on the mobile platform, and performs real-time control according to the acquired mobile visual positioning information to achieve speed synchronization with the mobile platform.

12. The system according to claim 11, wherein The system further includes: an altitude adjustment module; The height adjustment module is configured to control the UAV to approach the mobile platform in the height direction until the mobile platform is within the visual perception range of the UAV when the horizontal relative distance is equal to the second set threshold.

13. The system according to claim 11, wherein The system further includes a fourth speed synchronization module; The fourth speed synchronization module is configured to, while the UAV obtains visual beacon information in real time, the UAV obtains GNSS information of the mobile platform in real time; compare the deviation between the GNSS information and the visual beacon information obtained at the same moment; when the deviation is greater than or equal to the third set threshold, filter the GNSS information and the visual beacon information obtained at the same moment to obtain fusion control information; the UAV performs real-time control according to the fusion control information to achieve speed synchronization with the mobile platform.

14. The system according to claim 11, wherein The system further includes a landing module; The landing module is configured to, after the UAV is directly above the mobile platform, the UAV receives a landing instruction and lands on the landing area of the mobile platform according to the landing instruction.

15. A drone, characterized in that, Comprising the flight control system according to any one of claims 11 to 14.

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