Speed ​​synchronization control method for unmanned aerial vehicle and mobile platform, flight control system and unmanned aerial vehicle

Abstract

The present disclosure relates to the field of drone control technology, and more specifically to a method for speed synchronization control between a drone and a mobile platform, a flight control system, and a drone. The speed synchronization control method comprises: obtaining GNSS information, visual beacon information, or mobile visual positioning information based on the relative distance between the drone and the mobile platform, and utilizing the obtained GNSS information, visual beacon information, or mobile visual positioning information to control the drone in real time to achieve speed synchronization with the mobile platform. The present disclosure uses multiple speed synchronization methods to complement and assist each other, and can automatically select the optimal speed synchronization method for different distance ranges, thereby achieving precise speed synchronization between the drone and the mobile platform in complex environments, enabling the drone to achieve precise following or precise landing with the mobile platform.

Description

Technical Field

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

[0002] With the continuous development of drone technology, drones have been widely used in a variety of fields, including agriculture, surveying and mapping, power inspection, and disaster relief. During missions, drones often need to dock with mobile platforms such as vehicles and ships. This requires the drone to maintain the same speed and trajectory as the mobile platform for precise tracking and landing. However, existing technologies present certain difficulties in synchronizing the speed of drones and mobile platforms. The synchronization accuracy and stability need to be improved, and the system lacks flexibility to adapt to different scenarios.

[0003] Currently, speed synchronization between drones and mobile platforms relies primarily on GPS positioning or image matching. However, these methods suffer from low reliability and efficiency in practical applications, and require operators with extensive experience to flexibly control the drones. Therefore, finding a simple program to achieve precise speed synchronization between drones and mobile platforms has become a pressing issue. Summary of the Invention

[0004] In order to solve the problems in the related art, embodiments of the present disclosure provide a method for synchronously controlling the speed of a drone and a mobile platform, a flight control system, and a drone.

[0005] In a first aspect, an embodiment of the present disclosure provides a method for synchronously controlling the speed of a drone and a mobile platform, comprising:

[0006] The UAV receives a speed synchronization control instruction sent by a remote controller, and approaches the mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is arranged on the mobile platform;

[0007] 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 based on the acquired GNSS information to achieve speed synchronization with the mobile platform;

[0008] 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;

[0009] 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 by identifying the characteristic markers on the mobile platform, and performs real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0010] 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 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.

[0011] According to an embodiment of the present disclosure, the method further includes:

[0012] While the UAV is acquiring the visual beacon information in real time, the UAV is also acquiring the GNSS information of the mobile platform in real time; comparing the deviation between the GNSS information and the visual beacon information acquired at the same time; and when the deviation is greater than or equal to a third set threshold, filtering the GNSS information and the visual beacon information acquired at the same time to obtain fusion control information;

[0013] The UAV is controlled in real time according to the fused control information to achieve speed synchronization with the mobile platform.

[0014] According to an embodiment of the present disclosure, the method further includes:

[0015] After the UAV is directly above the mobile platform, the UAV receives a landing instruction and lands in a landing area of ​​the mobile platform according to the landing instruction.

[0016] According to an embodiment of the present disclosure, the GNSS information includes: the GNSS vector velocity and GNSS position of the mobile platform, and the GNSS position of the UAV;

[0017] 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 UAV, and generating a first speed control instruction based on the first speed to control the UAV to achieve speed synchronization with the mobile platform.

[0018] According to an embodiment of the present disclosure, the first speed is calculated according to the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV, and is implemented by the following formula:

[0019] ;

[0020] ;

[0021] ;

[0022] in, is the first speed, is the first proportional coefficient, is the first velocity 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.

[0023] 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 drone image transmission picture, and the visual beacon position of the drone;

[0024] 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.

[0025] According to an embodiment of the present disclosure, the second speed is calculated based on the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the drone, and is implemented by the following formula:

[0026] ;

[0027] ;

[0028] ;

[0029] in, is the second speed, is the second proportional 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.

[0030] 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 image transmission picture, and the visual positioning position of the drone;

[0031] The performing real-time control according to the mobile visual positioning information to achieve speed synchronization with the mobile platform includes:

[0032] A third speed is calculated based on the visual positioning position and visual positioning speed of the mobile platform and the visual positioning position of the UAV, and a third speed control instruction is generated based on the third speed to control the UAV to achieve speed synchronization with the mobile platform.

[0033] According to an embodiment of the present disclosure, the third speed is calculated based on the visual positioning position and the visual positioning speed of the mobile platform and the visual positioning position of the drone, and is implemented by the following formula:

[0034] ;

[0035] ;

[0036] ;

[0037] in, is the third speed, is the third proportional 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 UAV, is the real-time visual positioning position difference vector between the mobile platform and the UAV, is the initial visual positioning position vector of the UAV, is the initial visual positioning position vector of the mobile platform, is the real-time visual positioning position vector of the UAV, is the real-time visual positioning position vector of the mobile platform.

[0038] In a second aspect, an embodiment of the present disclosure provides a flight control system, which is provided on a drone and includes:

[0039] a receiving module configured to receive a speed synchronization control instruction sent by a remote controller, and approach a mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is disposed on the mobile platform;

[0040] 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, cause the UAV to acquire GNSS information in real time and perform real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform;

[0041] 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, cause the UAV to acquire visual beacon information in real time, and perform real-time control based on the acquired visual beacon information to achieve speed synchronization with the mobile platform;

[0042] 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, obtain mobile visual positioning information in real time by identifying characteristic marks on the mobile platform, and perform real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0043] According to an embodiment of the present disclosure, the system further comprises: a height adjustment module;

[0044] The height adjustment module is configured to 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 when the horizontal relative distance is equal to the second set threshold.

[0045] According to an embodiment of the present disclosure, the system further includes a fourth speed synchronization module;

[0046] The fourth speed synchronization module is configured to obtain the GNSS information of the mobile platform in real time while the UAV obtains the visual beacon information in real time; compare the deviation between the GNSS information and the visual beacon information obtained at the same time; 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 time 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.

[0047] According to an embodiment of the present disclosure, the system further comprises a landing module;

[0048] The landing module is configured to receive a landing instruction when the UAV is directly above the mobile platform, and land in a landing area of ​​the mobile platform according to the landing instruction.

[0049] In a third aspect, an embodiment of the present disclosure provides a drone, comprising a flight control system as described in any one of the second aspects.

[0050] According to the technical solution provided by the embodiments of the present disclosure, a drone receives a speed synchronization control instruction sent by a remote controller set on a mobile platform, and approaches the mobile platform in a horizontal direction 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 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 drone obtains visual beacon information in real time; 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 in real time, so that when the horizontal relative distance meets the range of different set thresholds, the drone is controlled in real time according to the obtained GNSS information, visual beacon information or mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0051] The present invention can automatically select the optimal speed synchronization method for different distance ranges in complex and changeable working scenarios, and realize accurate speed synchronization between the UAV and the mobile platform in complex environments, so that the UAV can achieve accurate following or accurate landing with the mobile platform, significantly reducing the dependence on the operator's experience, effectively overcoming the shortcomings of adopting a single synchronization method, and improving the accuracy and flexibility of speed synchronization. It can be widely used in agriculture, surveying and mapping, power inspection, disaster relief and other fields.

[0052] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objectives and advantages of the present disclosure will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0054] Figure 1 A flow chart showing a method for speed synchronization control between a drone and a mobile platform according to an embodiment of the present disclosure is shown;

[0055] Figure 2 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone 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 is shown;

[0056] Figure 3 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone 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;

[0057] Figure 4 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone and a mobile platform when the horizontal relative distance is less than a second set threshold until the drone is directly above the mobile platform in an embodiment of the present disclosure;

[0058] Figure 5 A structural block diagram of a flight control system according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0059] 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 the sake of clarity, parts not related to the description of the exemplary embodiments are omitted in the accompanying drawings.

[0060] In the present disclosure, it should be understood that terms such as "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the present specification, and are not intended to exclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof exist or are added.

[0061] It should also be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0062] In this disclosure, if it involves operations of obtaining user information or user data or displaying user information or user data to others, such operations are all authorized and confirmed by the user, or actively selected by the user.

[0063] As mentioned above, existing technologies for synchronizing the speed of drones and mobile platforms primarily rely on GPS positioning or image matching. However, these methods suffer from low reliability and efficiency in practical applications, and require extensive operator experience to flexibly control the drones. Therefore, achieving precise speed synchronization between drones and mobile platforms using a simple program has become a pressing issue.

[0064] In the present disclosure, a drone receives a speed synchronization control instruction sent by a remote controller set on a mobile platform, and approaches the mobile platform in a horizontal direction 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 obtains GNSS information in real time, and performs real-time control based on 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 or equal to a second set threshold, the drone obtains visual beacon information in real time, and performs real-time control based on 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 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 in real time by identifying characteristic marks on the mobile platform, and performs real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0065] The present disclosure can automatically select the optimal speed synchronization method for different distance ranges, and achieve precise speed synchronization between the UAV and the mobile platform in complex environments, so that the UAV can achieve precise following or precise landing with the mobile platform.

[0066] Figure 1 FIG. 1 is a flow chart showing a method for controlling the speed synchronization of a drone and a mobile platform according to an embodiment of the present disclosure. Figure 1 As shown, the speed synchronization control method includes the following steps S101 to S104:

[0067] In step S101, the drone receives a speed synchronization control instruction sent by a remote controller, and approaches the mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is set on the mobile platform.

[0068] Among them, the remote control is the core device for users to interact with the drone, and transmits operating instructions to the drone through wireless communication technology. The mobile platform serves as the carrier of the remote control, which can be a car, a movable ground station, a ship, etc. The remote control can be set in various forms on the mobile platform. For example, the remote control can be held by the driver on the mobile platform, or the remote control can be directly fixed on the mobile platform.

[0069] In the present disclosure, when the user wants to turn on speed synchronization, the user can send a speed synchronization command to the drone through the remote control. After receiving the speed synchronization command, the drone continuously approaches the mobile platform in the horizontal direction under the control of the remote control, and performs real-time speed synchronization control during the approach process.

[0070] In step S102, 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 based on the obtained GNSS information to achieve speed synchronization with the mobile platform.

[0071] The inventors noticed that the mobile platform is a key device that provides necessary support and cooperation for the drone to take off, land, and carry out various related operations on the ground. 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.

[0072] Based on this spatial position relationship, the technical solution disclosed in the present invention achieves simplified operation. Specifically, when processing problems such as motion planning, positioning, and coordinated control related to drones and mobile platforms within a set distance range, there is no need to take the altitude vector into consideration, only the horizontal relative distance needs to be considered. This simplified processing can not only reduce the computational complexity and improve the system's response speed and operating efficiency, but also reduce to a certain extent the errors that may be caused by considering too many variables, thereby providing a more reliable and efficient solution for the speed synchronization control of drones and mobile platforms.

[0073] In the present disclosure, the first set threshold can be customized, for example, it can be 50 meters, 60 meters, etc.

[0074] Specifically, the GNSS information includes: the GNSS vector velocity and GNSS position of the mobile platform, and the GNSS position of the UAV.

[0075] 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 UAV, and generating a first speed control instruction based on the first speed to control the UAV to achieve speed synchronization with the mobile platform.

[0076] Specifically, the first speed can be calculated based on the first proportional coefficient, the first speed feedforward coefficient, the real-time speed of the mobile platform, the initial position difference vector and the real-time position difference vector between the drone and the mobile platform, the initial position vector and the real-time position vector of the drone, and the initial position vector and the real-time position vector of the mobile platform.

[0077] The first proportional coefficient is used when calculating the first speed. In a drone speed control scenario, a control variable is generated based on the deviation between the current drone speed and the mobile platform speed (i.e., the speed error). The proportional coefficient determines the linear relationship between this control variable and the speed error.

[0078] The first velocity feedforward coefficient is used when calculating the first velocity. When the drone is following a mobile platform, a feedforward control variable needs to be directly generated based on the mobile platform's set velocity. The velocity feedforward coefficient is the parameter used to adjust the relationship between this feedforward control variable and the set velocity.

[0079] The first proportional coefficient and the first velocity feedforward coefficient can be set based on experience, for example, as a fixed value or an adaptive setting. For example, the first proportional coefficient is 3 to 5, and the first velocity feedforward coefficient is 0 to 1, which can be set as needed. It should be understood by those skilled in the art that the set values ​​of the first proportional coefficient and the first velocity feedforward coefficient are not intended to limit the scope of protection of this disclosure.

[0080] Furthermore, the first speed is calculated according to the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV, and is implemented by the following formula:

[0081] ;

[0082] ;

[0083] ;

[0084] in, is the first speed, is the first proportional coefficient, is the first velocity 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.

[0085] In the present disclosure, since the height vector does not need to be taken into consideration when achieving speed synchronization within a 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.

[0086] Since the first speed is calculated when the horizontal relative distance between the UAV and the mobile platform is greater than or equal to the first set threshold, the initial position difference vector between the UAV and the mobile platform is and the real-time position difference vector are both greater than or equal to the first set threshold.

[0087] Assumptions , , then item B can ensure the real-time tracking 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.

[0088] Figure 2 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone 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 is shown.

[0089] exist Figure 2 In a specific embodiment shown, the pilot of the drone is on a mobile platform and receives the GNSS vector velocity and GNSS position of the mobile platform through a remote control and transmits them to the drone; the drone calculates a first speed based on the GNSS vector velocity and GNSS position of the mobile platform obtained through the remote control and in combination with the GNSS position of the drone obtained by its own measurement, and generates a first speed control instruction based on this to control the speed synchronization of the drone and the mobile platform. Through the speed synchronization of the two, the relative synchronous motion of the drone and the mobile platform can be achieved, that is, the speed is consistent and the relative position is maintained within a certain range, or the horizontal motion trajectory of the drone can be made parallel to the motion trajectory of the mobile platform.

[0090] Furthermore, the pilot can adjust the relative position between the drone and the mobile platform using the remote controller's joystick. As the pilot manipulates the joystick, the initial position difference vector between the drone and the mobile platform changes accordingly. At this point, the initial position difference vector after releasing the joystick serves as the new initial position difference vector to regenerate the first velocity, thereby maintaining velocity synchronization between the drone and the mobile platform.

[0091] 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 visual beacon information in real time, and performs real-time control based on the obtained visual beacon information to achieve speed synchronization with the mobile platform.

[0092] 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 drone image transmission picture, and the visual beacon position of the drone.

[0093] In this disclosure, the term "drone image transmission" refers to the transmission of real-time captured images or video data by the drone via the image transmission system to a receiving device (such as a remote control screen, mobile phone, tablet computer, etc.), allowing the operator to view the content of the drone's captured images in real time. The term "visual beacon position" refers to the spatial coordinate vector of a target detected by the drone's visual sensors (such as a camera or depth camera) within the drone's image transmission image. The term "visual beacon velocity" refers to the target's motion velocity vector within the drone's image transmission image. In other words, visual beacon information is coordinates within the image transmission coordinate system and is a two-dimensional variable.

[0094] 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.

[0095] Specifically, the second speed can be calculated based on the second proportional coefficient, the 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 drone, the initial visual beacon position vector and the real-time visual beacon position vector of the drone, and the initial visual beacon position vector and the real-time visual beacon position vector of the mobile platform.

[0096] Similarly, the second proportional coefficient and the second speed feed-forward coefficient can be set based on experience, for example, they can be set to fixed values ​​or adaptive settings.

[0097] Furthermore, the second speed is calculated according to the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV, and is implemented by the following formula:

[0098] ;

[0099] ;

[0100] ;

[0101] in, is the second speed, is the second proportional 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.

[0102] 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 between the UAV and the mobile platform is and the real-time position difference vector are both smaller than the first set threshold and larger than the second set threshold.

[0103] Figure 3 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone 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 is shown.

[0104] exist Figure 3 In a specific embodiment shown, the drone collects images of the mobile platform through the image transmission camera. The user selects and marks the mobile platform in the drone's image transmission screen. The drone locks the mobile platform as the target, obtains the visual beacon position and visual beacon speed of the mobile platform, and calculates the second speed based on its own visual beacon position. Based on this, a second speed control instruction is generated to control the speed synchronization of the drone and the mobile platform. The relative synchronous movement of the drone and the mobile platform is achieved through the speed synchronization of the two.

[0105] Similarly, the pilot can also adjust the relative position between the drone and the mobile platform through the joystick of the remote controller to re-determine the new initial visual beacon position difference vector to regenerate the second speed to continue to maintain speed synchronization between the drone and the mobile platform.

[0106] In the present disclosure, the second set threshold may need to be set, and the second set threshold is smaller than the first set threshold. Assuming that the first set threshold is 30 meters, the second set threshold may be 5 meters, 1 meter, 0.5 meters, and so on.

[0107] The inventors found that although the speed determined by using GNSS information for speed control is relatively accurate, it may cause jumps, thereby affecting the user experience of the drone during actual control, such as jitter. Using visual beacon information for speed control, the speed determined is smoother, but the accuracy is slightly reduced. If GNSS information and visual beacon information can be comprehensively considered, the final speed determined can improve the jitter of the drone while also ensuring the accuracy of speed synchronization control.

[0108] According to an embodiment of the present disclosure, while the UAV obtains the visual beacon information in real time, the UAV also obtains the GNSS information of the mobile platform in real time; the deviation between the GNSS information and the visual beacon information obtained at the same time is compared; when the deviation is greater than or equal to a third set threshold, the GNSS information and the visual beacon information obtained at the same time are filtered to obtain fusion control information; the UAV is controlled in real time according to the fusion control information to achieve speed synchronization with the mobile platform.

[0109] The filtering may be a Kalman filter, a particle filter, a complementary filter, etc., but is not limited thereto, as long as it can achieve filtering of the GNSS information and the visual beacon information.

[0110] In step S104, when the mobile platform is within the visual perception range of the UAV and the horizontal relative distance is less than or equal to the second set threshold until the UAV is directly above the mobile platform, the UAV obtains mobile visual positioning information in real time by identifying the characteristic marks on the mobile platform, and performs real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0111] In the present disclosure, a landing area is provided on a mobile platform. The UAV being located directly above the mobile platform can be understood as meaning that the relative horizontal distance between the UAV and the margins of the landing area is a very small deviation or zero, or that the relative horizontal distance between the UAV and the center point of the landing area is a very small deviation or zero.

[0112] 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.

[0113] The visual perception range refers to the range within which the UAV can effectively identify and perceive the mobile platform through its visual sensors (such as cameras). Within this range, the UAV can capture sufficient visual information to locate / navigate the mobile platform.

[0114] 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 image transmission picture, and the visual positioning position of the drone.

[0115] In this disclosure, when acquiring mobile visual positioning information, the drone not only transmits the original image captured by the camera, but also uses image processing algorithms to identify characteristic markers on the mobile platform and determine the mobile platform's visual positioning position and speed. This information is then superimposed on the original image to form an enhanced image transmission image that incorporates the visual positioning information.

[0116] According to an embodiment of the present disclosure, the real-time control based on 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, and visual positioning position of the mobile platform, and generating a third speed control instruction based on the third speed to control the drone to achieve speed synchronization with the mobile platform.

[0117] Specifically, the third speed can be calculated based on the third proportional coefficient, the third speed feedforward coefficient, the real-time visual positioning speed of the mobile platform, the initial visual positioning position difference vector and the real-time visual positioning position difference vector between the mobile platform and the drone, the initial visual positioning position vector and the real-time visual positioning position vector of the drone, and the initial visual positioning position vector and the real-time visual positioning position vector of the mobile platform.

[0118] Likewise, the third proportional coefficient and the third speed feedforward coefficient can be customized according to actual needs.

[0119] Furthermore, the third speed is calculated according to the visual positioning position and the visual positioning speed of the mobile platform and the visual positioning position of the UAV, and is implemented by the following formula:

[0120] ;

[0121] ;

[0122] ;

[0123] in, is the third speed, is the third proportional 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 UAV, is the real-time visual positioning position difference vector between the mobile platform and the UAV, is the initial visual positioning position vector of the UAV, is the initial visual positioning position vector of the mobile platform, is the real-time visual positioning position vector of the UAV, is the real-time visual positioning position vector of the mobile platform.

[0124] It is known that the initial visual positioning position difference vector between the mobile platform and the UAV needs to satisfy a second set threshold value or less until it is zero. Therefore, the initial visual positioning position difference vector between the mobile platform and the UAV and the mobile platform The real-time visual positioning position difference vector between the UAV and It needs to be less than or equal to the second set threshold until it is 0. When the initial visual positioning position difference vector is zero, the drone is directly above the mobile platform. .

[0125] Figure 4 A schematic diagram illustrating an application scenario of the method for controlling the speed synchronization between a drone and a mobile platform when the horizontal relative distance is less than a second set threshold until the drone is directly above the mobile platform in an embodiment of the present disclosure.

[0126] exist Figure 4 In a specific embodiment shown, the drone obtains characteristic markers on the mobile platform through a visual sensor, and identifies the characteristic markers on the mobile platform through an image processing algorithm, determines the visual positioning position and visual positioning speed of the mobile platform, and calculates the third speed in combination with its own visual positioning position vector, and generates a third speed control instruction based on this to control the drone to synchronize with the mobile platform speed, so that the drone can remain above the mobile platform.

[0127] According to an embodiment of the present disclosure, after the UAV is directly above the mobile platform, the UAV receives a landing instruction and lands in a landing area of ​​the mobile platform according to the landing instruction.

[0128] The present invention can be used for complex and changeable working scenarios, integrates multiple speed synchronization methods, and 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 complex environments, so that the UAV can achieve accurate following or accurate landing with the mobile platform, significantly reducing the dependence on the operator's experience, effectively overcoming the shortcomings of adopting a single speed synchronization method, and improving the accuracy and flexibility of speed synchronization.

[0129] Figure 5 A structural block diagram of a flight control system 500 according to an embodiment of the present disclosure is shown.

[0130] The flight control system is set on the UAV. Figure 5 As 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 .

[0131] The receiving module 510 is configured to receive a speed synchronization control instruction sent by a remote controller, and approach the mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is set on the mobile platform.

[0132] The first speed synchronization module 520 is configured to, when the horizontal relative distance between the UAV and the mobile platform is greater than or equal to a first set threshold, cause the UAV to obtain GNSS information in real time, and perform real-time control based on the obtained GNSS information to achieve speed synchronization with the mobile platform.

[0133] The second speed synchronization module 530 is configured to, when the horizontal relative distance is less than the first set threshold and greater than the second set threshold, cause the drone to obtain visual beacon information in real time, and perform real-time control based on the obtained visual beacon information to achieve speed synchronization with the mobile platform.

[0134] 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, obtain the mobile visual positioning information in real time by identifying the characteristic markers on the mobile platform, and perform real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

[0135] According to an embodiment of the present disclosure, the system further includes: a height adjustment module, configured to 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 when the horizontal relative distance is equal to the second set threshold.

[0136] According to an embodiment of the present disclosure, the system also includes: a fourth speed synchronization module, which is configured to, while the UAV obtains the visual beacon information in real time, the UAV obtains the 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 time; 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 time 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.

[0137] According to an embodiment of the present disclosure, the system further includes: the landing module, which is configured to receive a landing instruction after the drone is directly above the mobile platform, and land in a landing area of ​​the mobile platform according to the landing instruction.

[0138] The present disclosure also discloses a drone, comprising the flight control system as described in any of the previous embodiments.

[0139] The UAV achieves speed synchronization control with the mobile platform through the flight control system.

[0140] The units or modules involved in the embodiments described in this disclosure may be implemented by software or programmable hardware. The units or modules described may also be provided in a processor, and the names of these units or modules do not, in certain circumstances, constitute limitations on the units or modules themselves.

[0141] The above description is merely a preferred embodiment of the present disclosure and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to technical solutions formed by specific combinations of the aforementioned technical features. It also encompasses other technical solutions formed by any combination of the aforementioned technical features or their equivalents, without departing from the inventive concept. For example, a technical solution formed by replacing the aforementioned features with (but not limited to) technical features with similar functions disclosed in this disclosure.

Claims

1. A method for synchronously controlling the speed of a drone and a mobile platform, characterized in that: include: The UAV receives a speed synchronization control instruction sent by a remote controller, and approaches the mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is arranged 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 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, the GNSS information including: a GNSS vector velocity and a GNSS position of the mobile platform, and a GNSS position of the UAV, wherein the GNSS vector velocity and the GNSS position of the mobile platform, and the GNSS position of the UAV are all two-dimensional variables that do not include altitude; 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 based on the acquired visual beacon information to achieve speed synchronization with the mobile platform, including: while the UAV acquires the visual beacon information in real time, the UAV acquires 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 time, and 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 time to obtain fusion control information, and the UAV performs real-time control based on the fusion control 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 or equal to the second set threshold until the UAV is directly above the mobile platform, the UAV obtains mobile visual positioning information in real time by identifying the characteristic marks on the mobile platform, and performs real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

2. The method according to claim 1, characterized in that 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.

3. The method according to claim 1, characterized in that The method further comprises: After the UAV is directly above the mobile platform, the UAV receives a landing instruction and lands in a landing area of ​​the mobile platform according to the landing instruction.

4. The method according to claim 1, wherein: 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 UAV, and generating a first speed control instruction based on the first speed to control the UAV to achieve speed synchronization with the mobile platform.

5. The method according to claim 4, characterized in that The first speed is calculated according to the GNSS vector speed and GNSS position of the mobile platform and the GNSS position of the UAV, and is implemented by the following formula: ； ； ； in, is the first speed, is the first proportional coefficient, is the first velocity 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.

6. 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 UAV image transmission picture, and the visual beacon position of the UAV; 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.

7. The method according to claim 6, characterized in that The second speed is calculated according to the visual beacon position and visual beacon speed of the mobile platform and the visual beacon position of the UAV, and is implemented by the following formula: ； ； ； in, is the second speed, is the second proportional 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.

8. 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 UAV image transmission picture, and the visual positioning position of the UAV; The performing real-time control according to the mobile visual positioning information to achieve speed synchronization with the mobile platform includes: A third speed is calculated based on the visual positioning position and visual positioning speed of the mobile platform and the visual positioning position of the UAV, and a third speed control instruction is generated based on the third speed to control the UAV to achieve speed synchronization with the mobile platform.

9. The method according to claim 8, characterized in that The third speed is calculated based on the visual positioning position and the visual positioning speed of the mobile platform and the visual positioning position of the UAV, and is implemented by the following formula: ； ； ； in, is the third speed, is the third proportional 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 UAV, is the real-time visual positioning position difference vector between the mobile platform and the UAV, is the initial visual positioning position vector of the UAV, is the initial visual positioning position vector of the mobile platform, is the real-time visual positioning position vector of the UAV, is the real-time visual positioning position vector of the mobile platform.

10. A flight control system, characterized in that: The flight control system is provided on the UAV and includes: a receiving module configured to receive a speed synchronization control instruction sent by a remote controller, and approach a mobile platform in a horizontal direction under the control of the remote controller, wherein the remote controller is disposed 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, cause the UAV to acquire GNSS information in real time and perform real-time control based on the acquired GNSS information to achieve speed synchronization with the mobile platform, wherein the GNSS information includes: a GNSS vector velocity and a GNSS position of the mobile platform, and a GNSS position of the UAV, wherein the GNSS vector velocity and the GNSS position of the mobile platform, and the GNSS position of the UAV are all two-dimensional variables that do not include altitude; 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, cause the UAV to acquire visual beacon information in real time, and perform real-time control based on the acquired visual beacon information to achieve speed synchronization with the mobile platform, including: simultaneously with the UAV acquiring the visual beacon information in real time, the UAV acquires 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 time, and 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 time to obtain fusion control information, and the UAV performs real-time control based on the fusion control 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, obtain mobile visual positioning information in real time by identifying characteristic marks on the mobile platform, and perform real-time control based on the obtained mobile visual positioning information to achieve speed synchronization with the mobile platform.

11. The system according to claim 10, wherein: The system further comprises: a height adjustment module; The height adjustment module is configured to 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 when the horizontal relative distance is equal to the second set threshold.

12. The system according to claim 10, wherein: The system also includes a landing module; The landing module is configured to receive a landing instruction when the UAV is directly above the mobile platform, and land in a landing area of ​​the mobile platform according to the landing instruction.

13. A drone, characterized in that: Comprising a flight control system as described in any one of claims 10 to 12.

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