Control method and control system of traction unmanned aerial vehicle and traction system

Abstract

The invention relates to a control method, a control system and a traction system of a traction unmanned aerial vehicle. The traction unmanned aerial vehicle comprises a plurality of vertical rotors and two tension rotors. The rotation axis direction of each tension rotor wing is the first direction. The traction drone is configured to be connected to the unpowered aircraft through a traction rope. The control method comprises the following steps: acquiring a preset flight direction of the unpowered aircraft; the traction unmanned aerial vehicle is controlled to move to the front upper portion of the unpowered aircraft in the preset flight direction; and controlling the traction unmanned aerial vehicle to pull the unpowered aircraft to rise to a preset height through the traction rope. Wherein the step of controlling the traction unmanned aerial vehicle to pull the unpowered aircraft to rise to the preset height through the traction rope comprises the substeps that when the unpowered aircraft climbs, the angle between the first direction and the direction of the traction rope is controlled to be smaller than or equal to 20 degrees.

Description

Technical Field

[0001] This application relates to the field of towing unmanned aerial vehicles (UAVs) for unpowered aircraft, and in particular to a control method, control system, and towing system for a towing UAV. Background Technology

[0002] The applicant disclosed a towing drone in Chinese patent application publication number CN118701323A, which can be used to tow unpowered aircraft such as paragliders. The towing drone can provide traction to the unpowered aircraft via a towing rope to assist the unpowered aircraft in taking off.

[0003] The battery of a towing drone is typically one of its heaviest components. During the takeoff of an unpowered aircraft, its flight attitude and / or orientation can be controlled in real time by the operator. Changes in the flight attitude and / or orientation of the unpowered aircraft can reduce the towing efficiency of the towing drone, thereby increasing its energy consumption. This places higher demands on the battery capacity of the towing drone. Therefore, how to increase the towing efficiency of the towing drone on the unpowered aircraft, and thus reduce its battery capacity requirements, is a problem that urgently needs to be solved in this field. Summary of the Invention

[0004] This application provides a control method for towing unmanned aerial vehicles (UAVs) to improve the towing efficiency of UAVs on unpowered aircraft.

[0005] The first aspect of this application provides a control method for a towed unmanned aerial vehicle (UAV). The towed UAV includes multiple vertical rotors and two pull rotors. The towed UAV is configured to be connected to a non-powered aircraft via a tow rope. The control method includes: obtaining a preset flight direction of the non-powered aircraft; controlling the towed UAV to move forward and above the non-powered aircraft along the preset flight direction; and controlling the towed UAV to pull the non-powered aircraft up to a preset height via the tow rope. Specifically, controlling the towed UAV to pull the non-powered aircraft up to the preset height via the tow rope includes: controlling the angle between the first direction and the direction of the tow rope to be less than or equal to 20° during the ascent of the non-powered aircraft.

[0006] A second aspect of this application provides a control system. The control system includes a processor and a memory. The memory stores program code. The processor is configured to execute the program code to implement the aforementioned control method for a towed unmanned aerial vehicle.

[0007] A third aspect of this application provides a traction system. The traction system includes a traction drone and a powerless aircraft interconnected. The traction drone includes multiple vertical rotors and two pull rotors. The traction drone is configured to be connected to the powerless aircraft via a traction cable. The traction drone includes monitoring sensors configured to monitor the powerless aircraft. The traction system is configured with the aforementioned control method for the traction drone.

[0008] The control method for towing a drone disclosed in this application controls the angle between the rotation axis of the towing drone's pull rotor and the direction of the towing rope to be less than or equal to 20° during the paraglider's ascent. By controlling the angle between the first direction and the direction of the towing rope to be less than or equal to 20°, energy loss caused by severe altitude fluctuations between the towing drone and the towing rope can be reduced, improving the towing efficiency of the towing drone for unpowered aircraft, and helping to reduce the weight of the towing drone's battery pack, thereby reducing its production cost. Attached Figure Description

[0009] Figure 1 A schematic diagram of a traction system according to some embodiments of this application is shown;

[0010] Figure 2 A perspective view of a towing drone according to some embodiments of this application is shown;

[0011] Figure 3 A perspective view of a towing component of a towing drone according to some embodiments of this application is shown;

[0012] Figure 4 A perspective view of a paraglider according to some embodiments of this application is shown;

[0013] Figure 5 This invention illustrates a structural block diagram of a control station according to some embodiments of the present application;

[0014] Figure 6 This invention illustrates a structural block diagram of an intelligent recognition system according to some embodiments of the present application;

[0015] Figure 7 A schematic diagram of the paraglider body coordinate system according to some embodiments of this application is shown;

[0016] Figure 8 A flowchart illustrating a control method for a towed unmanned aerial vehicle according to some embodiments of this application is shown;

[0017] Figure 9 The diagram illustrates an implementation of a control method according to some embodiments of this application;

[0018] Figure 10 Some embodiments according to this application are shown. Figure 8 A flowchart illustrating step S30 in the process;

[0019] Figure 11 Other embodiments according to this application are shown. Figure 8 A flowchart illustrating step S30 in the process;

[0020] Figure 12 A flowchart illustrating a control method for towing an unmanned aerial vehicle according to other embodiments of this application is shown;

[0021] Figure 13 This invention provides a schematic diagram of the structure of a control system according to some embodiments of the present application.

[0022] Figure 14 A schematic diagram showing the relationship between the first included angle and the second included angle is provided.

[0023] Reference numerals: 10, Towing system; 100, Towing UAV; 200, Paraglider; 300, Control station; 110, Main structure; 120, Vertical rotor assembly; 122, Lifting arm; 124, Vertical rotor; 130, Strut rotor assembly; 132, Strut arm; 134, Strut rotor; 150, Towing assembly; 152, Winch; 154, Guide rod; 1522, Sleeve; 160, Battery pack; 211, Paraglider wing; 212, Paraglider lines; 213, Hanging seat; 214. Controller; 2111, Upper wing surface; 2112, Lower wing surface; 2113, Wing rib; 310, Communication equipment; 320, Data processing equipment; 330, Visualization terminal; 400, Tow rope; 500, Intelligent identification system; 510, Airborne processing unit; 520, Monitoring sensor; 530, Paraglider IMU; 540, Paraglider antenna; 550, Paraglider audio acquisition equipment; 600, Control system; 610, Processor; 620, Memory; 700, Cloud server. Detailed Implementation

[0024] The following describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0025] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0026] In this article, the term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, "more" in this article means two or more objects.

[0027] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified in some embodiments. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0028] refer to Figure 1-Figure 5 , Figure 1 This diagram illustrates a traction system 10 according to some embodiments of the present application. Figure 2 This paper shows a perspective view of a towing drone 100 according to some embodiments of this application. Figure 3 This is a perspective view of a towing assembly 150 of a towing drone 100 according to some embodiments of this application. Figure 4 A perspective view of a paraglider 200 according to some embodiments of this application is shown. Figure 5 A structural block diagram of a control station 300 according to some embodiments of this application is shown.

[0029] like Figure 1 As shown, the traction system 10 includes a towing drone 100 and a powerless aircraft that are communicatively connected to each other. The towing drone 100 is configured to be connected to the powerless aircraft via a towing rope 400.

[0030] In this application, a powerless aircraft refers to a device that does not rely on its own power source for propulsion, but achieves flight by utilizing natural forces such as wind, gravity, and airflow. Powerless aircraft may include, for example, a parachute 200, a fixed-wing glider, or a parachute. This application will describe a powerless aircraft as a parachute 200 as an example below. Those skilled in the art should understand that the parachute 200 described below can be replaced with other powerless aircraft.

[0031] In some embodiments, such as Figure 1 As shown, the traction system 10 may also include a control station 300.

[0032] refer to Figure 5 The control station 300 may include communication equipment 310, data processing equipment 320, and visualization terminal 330, etc. The control station 300 may be, for example, a fixed control station or a mobile control station. For instance, the control station 300 may be a ground control station, a vehicle-mounted control station, a ship-mounted control station, etc. In some embodiments, the control station 300 may also be implemented as a portable terminal such as a laptop computer, tablet computer, or mobile phone. This application does not limit the specific implementation method and implementation carrier of the control station 300.

[0033] The communication device 310 can be configured to enable wireless communication between the control station 300 and the towed drone 100 and / or the paraglider 200. The communication device 310 can also be configured to enable real-time command interaction between the control station 300 and the towed drone 100 and / or the paraglider 200.

[0034] The data processing device 320 can be configured to process images or videos from the towed drone 100 to determine the flight altitude, flight attitude, and flight direction of the paraglider 200. The data processing device 320 can also be configured to process attitude data from the IMU (inertial measurement unit) sensors of the towed drone 100 and / or the paraglider 200, as well as environmental parameters collected from meteorological monitoring equipment, to determine the flight altitude, flight speed, and / or flight attitude of the paraglider 200 and / or the towed drone 100. The data processing device 320 can be configured to process pressure or acoustic data from the paraglider 200 to determine the state of the paraglider 200, for example, whether the paraglider 200 is in a stall state. In some embodiments, the data processing device 320 may also include a cloud server 700 or a remote server, etc., which is not specifically limited in this application.

[0035] The visualization terminal 330 can be configured to display at least one of the following: an image of the paraglider 200's attitude captured by the towing drone 100; the three-dimensional spatial trajectory of the paraglider 200 and / or the drone; the real-time flight altitude of the paraglider 200 and / or the drone; instantaneous wind speed and direction; air pressure and temperature, etc. In emergency situations such as the towing system 10 detecting a risk of stall in the paraglider 200 or excessive wind speed, the visualization terminal 330 can also display an alarm.

[0036] With the cooperation of the aforementioned communication equipment 310, data processing equipment 320 and visualization terminal 330, the control station 300 in this application can provide comprehensive safety assurance and decision support for drone pilots or paraglider operators 200.

[0037] refer to Figure 2 , Figure 2 A perspective view of a towing drone 100 according to some embodiments of this application is shown.

[0038] like Figure 2 As shown, the towing drone 100 includes two pull rotors 134 and multiple vertical rotors 124. The multiple vertical rotors 124 can be configured to be centrally symmetrically distributed to provide the lift, steering force, etc. required by the towing drone 100. Figure 2 The diagram shows a towing drone 100 comprising four vertical rotors 124. The towing drone 100 may also include six or more vertical rotors 124; this application is not limited thereto. Each towing rotor 134 or vertical rotor 124 may include multiple blades, such as two, three, or more; this application is not specifically limited thereto. This is provided as an example, not as a limitation. Figure 2 The diagram shows that each rotor consists of two blades arranged opposite each other.

[0039] When a rotor rotates, the trailing trajectories of its blades form a circle, and the plane containing this circle is called the plane of rotation of the rotor. The central axis around which the rotor blades rotate is called the axis of rotation of the rotor. In this application, the axis of rotation of each pull rotor 134 can be labeled as a first direction. This first direction can form a first angle with the plane of rotation of the vertical rotor 124. The first angle can be an acute angle. The first angle can be any angle between 5° and 30°. In some embodiments, the first angle can be any angle between 10° and 15°, such as 10°, 12°, 15°, etc. By configuring the first direction of the pull rotor 134 to form a first angle with the plane of rotation of the vertical rotor 124, the pull rotor 134 can be dedicated to providing traction for the paraglider 200, and the vertical rotor 124 can be dedicated to achieving attitude and trajectory control of the towing drone 100 itself. In this way, the magnitude of the traction force provided to the paraglider 200 can be controlled simply by adjusting the rotation speed of the traction rotor 134, thereby simplifying the control complexity of the towing drone 100.

[0040] In some embodiments, the towing drone 100 may include a tension arm 132. The middle portion of the tension arm 132 is configured as the center of gravity of the towing drone 100. Two tension rotors 134 are symmetrically fixed on both sides of the middle portion of the tension arm 132. One end of the towing rope 400 is connected to the middle portion of the tension arm 132. Because the two tension rotors 134 are symmetrically fixed on both sides of the middle portion of the tension arm 132, and the middle portion of the tension arm 132 is configured as the center of gravity of the towing drone 100, the tension generated by the two tension rotors 134 can directly act on the center of gravity of the towing drone 100, eliminating the influence of the tension generated by the tension rotors 134 on the attitude of the towing drone 100, reducing the complexity of attitude adjustment of the towing drone 100, and improving system reliability. At the same time, this arrangement also reduces the additional energy consumption for attitude adjustment of the towing drone 100 and improves the energy utilization efficiency of the towing drone 100. Furthermore, in some embodiments, one end of the tow rope 400 is connected to the middle of the pull arm 132, which serves as the center of gravity of the towing drone 100. This also reduces the torque exerted by the glider 200 on the towing drone 100, reduces the vibration generated by the glider 200's pulling action, and improves the reliability of the towing drone 100.

[0041] Specifically, such as Figure 2 As shown, the towing drone 100 may include a structural body 110, a vertical rotor assembly 120, a thrust rotor assembly 130, a towing assembly 150, an energy system (not shown in the figure), avionics and flight control components, etc.

[0042] The vertical rotor assembly 120 may include a lifting arm 122 and a vertical rotor 124 fixed to the lifting arm 122. The vertical rotor 124 may include blades and a motor (not shown) for driving the blades to rotate. The lifting arm 122 may be fixedly mounted to the structure body 110.

[0043] The pull rotor assembly 130 may include a pull arm 132 as described above and two pull rotors 134 symmetrically fixed to the pull arm 132. Each pull rotor 134 may include blades and a motor (not shown) for driving the blades to rotate. The pull arm 132 may be fixedly mounted to the structural body 110.

[0044] The energy system may include a battery pack 160 and an electronic speed controller (ESC) assembly. The battery pack 160 can be electrically connected via the ESC assembly to the motors used to drive the blades of the vertical rotor 124 or the thrust rotor 134. Under the control of the avionics and flight control system, the ESC assembly can adjust the magnitude and direction of the current input to the motors to control the rotational speed of the corresponding rotor. The energy system can be fixedly mounted to the structural body 110.

[0045] The towing assembly 150 is used to connect to or retract the towing rope 400 used to tow the paraglider 200. For example... Figure 3 As shown, the traction assembly 150 may include a winch 152 directly or indirectly connected to the structure body 110. The winch 152 is configured to retrieve, deploy, and / or store the traction rope 400. One end of the traction rope 400 is disposed on the winch 152 for traction of the drone 100.

[0046] like Figure 2 As shown, the winch 152 and the lifting arm 132 are arranged side by side. In some embodiments, the winch 152 is sleeved on the lifting arm 132, particularly on the middle portion of the lifting arm 132. Figure 3 As shown, Figure 3 A schematic diagram of a traction assembly 150 according to some embodiments of this application is shown. Figure 3 As shown, the winch 152 can limit the sleeve 1522, which can be sleeved on the middle of the tension arm 132.

[0047] The towing assembly 150 of the towing drone 100 may also include a guide rod 154, and a towing rope 400 released from the winch 152 may extend along the guide rod 154 in a direction away from the towing drone 100 until it is connected to the paraglider 200. The guide rod 154 may be set perpendicular to the pull arm 132 and may rotate freely within a certain angle range in a plane perpendicular to the pull arm 132 under the action of the towing rope 400.

[0048] Optionally, the traction assembly 150 may also include a tension sensor (not shown). The tension sensor is configured to detect the tension, also known as traction force, of the traction rope 400.

[0049] The avionics and flight control components are configured to provide attitude control, communication, and navigation for the towed UAV 100, ensuring flight safety and enabling the UAV to fly according to its design specifications. The avionics and flight control components may consist of at least one of the following: a flight control computer, radar, navigation equipment, data transmission equipment, altitude sensor, image transmission equipment, and antenna. The flight control computer controls the UAV's flight attitude to meet its requirements and simultaneously controls the tow rope 400 control device within the tow assembly 150, controlling its extension, retraction, and tension to ensure a safe distance between the UAV and the rear paraglider 200. The radar monitors the position of the rear paraglider 200 and feeds the monitored information back to the flight control computer, which then controls the UAV's flight attitude, such as ensuring the rear paraglider 200 is directly behind and below the UAV, thus ensuring the paraglider's safety. The navigation equipment provides a navigation system for the towed UAV 100, enabling it to fly along a planned route or airspace. The data transmission equipment can transmit control commands, sensor data, and other non-video data for remote control operation, flight status monitoring, sensor data acquisition, and transmission of the towed drone 100. By establishing a two-way link, the data transmission equipment allows ground control personnel to remotely monitor the drone's flight status and send commands for remote control operation. The video transmission equipment can transmit real-time video data, providing a real-time video stream captured by the towed drone 100's camera for real-time monitoring and operation by the control station 300 or ground operators, ensuring safety during flight. The altitude sensor can monitor the drone's altitude information in real time. The antenna provides signal transmission between the towed drone 100 and the control station 300 and / or the paraglider 200. The antenna also provides signal transmission between the towed drone 100 and positioning satellites, ensuring accurate positioning of the towed drone 100 and the accuracy and timeliness of information transmission.

[0050] The avionics and flight control components may also include a towed drone IMU. The towed drone IMU may include devices such as a three-axis accelerometer or a gyroscope. The towed drone IMU can be configured to measure the acceleration and angular velocity of the towed drone 100 in real time and monitor the attitude information of the towed drone 100.

[0051] refer to Figure 4 , Figure 4 A schematic diagram of the structure of a paraglider 200 according to some embodiments of this application is shown. For example... Figure 4 As shown, the paraglider 200 may include a wing 211, parachute lines 212, a saddle 213, and a control device 214.

[0052] The paraglider 211, also known as the airfoil canopy, is the main component of the paraglider 200 that generates lift and bears load. The paraglider 211 may consist of an upper wing surface 2111, a lower wing surface 2112, and several shaped ribs 2113 arranged along the wingspan of the paraglider 211. The upper wing surface 2111 and the lower wing surface 2112 may be made of flexible material. The upper wing surface 2111 and the lower wing surface 2112 are respectively sewn to the ribs 2113, thereby forming a specific shape of the paraglider 211. Generally, air chambers can be formed between the ribs 2113, which are closed at the top and bottom by the upper wing surface 2111 and the lower wing surface 2112, respectively. The leading edge of the paraglider 211 defines several air inlets for each air chamber. The trailing edge of the paraglider 211 may be closed. When the paraglider 211 moves relative to the air, air enters the air chambers through the air inlets, generating a certain pressure in the inner cavity of the paraglider 211, thus maintaining a certain rigidity and shape of the paraglider 211. The air between the air chambers can flow along the wingspan to balance the pressure inside the parachute 211 and prevent the parachute 211 from partially collapsing due to uneven force during inflation.

[0053] Paracord 212 can be used to connect parachute 211 and hanger 213.

[0054] The sling 213, also known as a harness assembly, seat strap, or sling, is used to secure and protect the operator of the paraglider 200; this application does not impose specific limitations on this. The sling 213 may also be equipped with a tow rope 400 connection mechanism. The tow rope 400 is releasably connected to the tow rope 400 connection mechanism, thereby connecting the paraglider 200 to the towed drone 100.

[0055] The manipulator 214, also known as a control system or control assembly, can be implemented as a control belt, control rope, control ring, control stick, foot pedal, etc. Figure 3 As shown, and by way of example rather than limitation, the manipulator 214 is implemented as at least two control lines connected to the paraglider 211211, specifically a left control line and a right control line connected to opposite sides of the paraglider 211 along its wingspan. The left control line is on the left side of the paraglider 200 operator, and the right control line is on the right side of the paraglider 200 operator. Pulling down the left control line enables the paraglider 200 to turn left, and pulling down the right control line enables the paraglider 200 to turn right. Pulling down both the left and right control lines simultaneously allows the operator to adjust the speed of the paraglider 200. The traction system 10 and traction method described in this application are also applicable to paragliders 200 including other types of manipulators 214214.

[0056] In some embodiments, the traction system 10 may further include an intelligent identification system 500. (See reference...) Figure 6 , Figure 6This diagram illustrates a structural block diagram of an intelligent identification system 500 for sports safety monitoring of a paraglider 200, according to some embodiments of this application. The intelligent identification system 500 may include an onboard processing unit 510 on a towing drone 100, monitoring sensors 520, etc.

[0057] Specifically, the towing drone 100 may additionally include or deploy an onboard processing unit 510 for neural network computing. This onboard processing unit 510 may be, for example, an onboard neural processing unit (NPU). The onboard neural processing unit may be equipped with an RK3588 chip. The onboard processing unit 510 may be fixedly connected to the towing drone 100; this application does not limit the specific installation location of the onboard processing unit 510 on the towing drone 100.

[0058] In some embodiments, the onboard processing unit 510 can be used to identify and track the paraglider 200. The onboard processing unit 510 can be configured to run a target identification and / or tracking module. This target identification and / or tracking module can be, for example, based on the DeepSORT tracking algorithm. The DeepSORT algorithm is a deep learning-based target tracking algorithm, short for deepsimple online and real-time tracking. The DeepSORT algorithm can be implemented as a neural network model. The DeepSORT algorithm combines detection algorithms (such as YOLO, Faster R-CNN, etc.), motion models (such as Kalman filtering), and appearance feature matching (features extracted by deep learning) to achieve continuous tracking of the target. The DeepSORT algorithm can improve the matching accuracy when the target is occluded for a period of time and / or when similar targets exist, thereby improving the identification and tracking accuracy. This target identification and / or tracking module can be, for example, based on other algorithms, such as TransT, TrackFormer, MTRAC, R-CNN, etc., and this application does not impose specific limitations on this.

[0059] The onboard processing unit 510 can be configured to process the sound data transmitted by the paraglider 200 to identify stall sound characteristics. For example, the onboard processing unit 510 can be configured to run sound recognition models such as X-vector, ECAPA-TDNN, SincNet, etc., to extract sound features or acoustic signatures corresponding to the stall phenomenon of the paraglider 200.

[0060] In some embodiments, the towing drone 100 may include a monitoring sensor 520 for monitoring the paraglider 200. The monitoring sensor 520 may be, for example, a camera, radar, or LiDAR. The camera may be, for example, an RGB gimbal camera. The monitoring sensor 520 of the towing drone 100 acquires images of the paraglider 200, distances between the paraglider 200 and the towing drone 100 at various positions. The onboard processing unit 510 of the towing drone 100 can process this information to dynamically identify attitude information such as the attitude angle and chord direction of the paraglider 200. The towing drone 100 may further combine this information with detected environmental wind speed information to determine the angle of attack of the paraglider 200.

[0061] This application, by deploying monitoring sensors 520 and an onboard neural network processing unit such as one equipped with an RK3588 chip on a towing drone 100, enables the acquisition of monitoring information (e.g., image acquisition), processing of monitoring information, and dynamic identification of the paraglider 200 and its attitude in complex airspace environments with a latency of less than 200 milliseconds. This includes identifying the pitch angle, heading angle, and other parameters of the paraglider 200. These parameters can be transmitted to the flight control components to determine whether the paraglider 200 has stalled, and to automatically adjust the flight parameters of the towing drone 100 when a stall risk or stall phenomenon is detected, helping the paraglider 200 escape the stall risk.

[0062] In some embodiments, the intelligent identification system 500 may further include a paraglider IMU 530 and / or a paraglider audio acquisition device 550. The paraglider IMU 530 may be installed on at least one side of the wing 211 of the paraglider 200. The paraglider IMU 530 may include devices such as a three-axis accelerometer and a gyroscope. The paraglider IMU 530 may be configured to measure the acceleration and angular velocity of the paraglider 200 in real time, monitor the attitude information of the paraglider 200, and transmit this attitude information to the towing drone 100. The paraglider audio acquisition device 550 may be, for example, an audio acquisition device such as a microphone or a microphone head. The paraglider audio acquisition device 550 may be arranged close to the upper wing surface 2111 of the wing 211. The towing drone 100 can integrate the attitude information of the paraglider 200 from the paraglider IMU 530, the attitude information of the paraglider 200 determined by the airborne processing unit 510, and / or the audio information from the paraglider 200, in order to better determine the attitude of the paraglider 200 and whether the paraglider 200 has stalled.

[0063] The paraglider 200 may also include a paraglider antenna 540. The paraglider antenna 540 can be used to conduct communication with the towing drone 100 and / or the control station 300. This application does not limit the band, shape, or mounting location of the paraglider antenna 540.

[0064] In some embodiments, the intelligent identification system 500 may further include the control station 300 and / or cloud server 700 described above. The control station 300 may be connected to the cloud server 700 via wired or wireless communication. The towing drone 100 and / or paraglider 200 may communicate with the control station 300, or communicate with the cloud server 700 through the control station 300. The control station 300 and / or cloud server 700 may determine the specific attitude of the paraglider 200 based on at least one of the paraglider 200 attitude information from the paraglider IMU 530, the information collected by the monitoring sensor 520, and the paraglider 200 attitude information determined by the airborne processing unit 510. The intelligent identification system 500 of this application may also exclude the cloud server 700, and this application does not impose any restrictions on this.

[0065] The intelligent recognition system 500 of this application integrates multiple sensors (including the paraglider IMU 530 and the monitoring sensor 520 on the towing drone 100) through the airborne processing unit 510, and realizes real-time accurate recognition and control of the attitude of the paraglider 200, which greatly improves the safety of the paraglider 200 movement.

[0066] The following section introduces the terminology that may be used in the description below.

[0067] Wingspan

[0068] The wingspan of an unpowered aircraft refers to the straight-line distance between the left and right ends of the aircraft's wings.

[0069] In the case where the unpowered aircraft is a fixed-wing aircraft, the wingspan is the straight-line distance between the two ends of the fixed wing.

[0070] In the case where the unpowered aircraft is a paraglider 200, refer to Figure 7 , Figure 7 A schematic diagram of the paraglider 200's body coordinate system is shown. (For example...) Figure 7 As shown, the coordinate system of the paraglider 200 can be a Cartesian coordinate system fixed to the body of the paraglider 200 (e.g., the rib 2113 of the wing 211). The coordinate system of the paraglider 200 can include an X-axis, a Y-axis, and a Z-axis. The X-axis represents the longitudinal direction of the paraglider 200, the Y-axis represents the vertical direction of the paraglider 200, and the Z-axis is perpendicular to the XY plane defined by the X and Y axes, i.e., the lateral direction of the paraglider 200. The wingspan L is the straight-line distance of the wing 211 of the paraglider 200 in the deployed state along the lateral direction Z. Figure 7 In the diagram, the longitudinal direction X represents the forward and backward direction of the paraglider 200.

[0071] Mean aerodynamic chord (MAC)

[0072] The mean aerodynamic chord is an imaginary straight line from the leading edge to the trailing edge of the airfoil, also known as the chord of the paraglider 211. An airfoil is the cross-sectional shape of an airfoil or paraglider 211 in a direction perpendicular to its length (wingspan direction), also known as an "airfoil profile".

[0073] In the case where the unpowered aircraft is a paraglider 200, such as Figure 7 As shown, the mean aerodynamic chord is an imaginary line segment C from the leading edge to the trailing edge of the airfoil 211.

[0074] Angle of attack (AOA)

[0075] Angle of attack is the angle between the mean aerodynamic chord of an unpowered aircraft and the direction of incoming flow (also known as the relative airflow direction). The relative airflow direction is the direction of airflow relative to the airfoil.

[0076] In the case where the unpowered aircraft is a paraglider 200, the angle of attack is the angle between the average aerodynamic chord of the wing 211 and the direction of the incoming flow.

[0077] Stall

[0078] Angle of attack affects the lift and drag coefficients of unpowered aircraft. When the angle of attack of an unpowered aircraft exceeds a certain critical value, the surface airflow separation on its airfoil intensifies, resulting in a sharp drop in lift and a surge in drag, causing the unpowered aircraft to lose its normal flight attitude. This phenomenon is called stall.

[0079] In the case of the unpowered aircraft being a paraglider 200, changes in the mean aerodynamic chord or the direction of incoming airflow leading to an increased angle of attack can cause the angle of attack to increase to the critical angle of attack corresponding to stall. The applicant observed that in the paraglider 200, stall can manifest as stall deformation of the wing 211, sudden descent of the wing 211, a sharp decrease in the speed of the wing 211, and a dramatic increase in the noise of the airflow above the wing 211. Stall deformation may include collapse, folding, wrinkling, or cave-in of the upper wing surface 2111. Stall deformation can occur in localized areas or large areas of the wing 211. If not addressed promptly, the paraglider 200 may enter a spiral descent state, potentially leading to serious consequences.

[0080] Paraglider 200 may also experience asymmetrical stall. Specifically, one wing 211 may stall first, causing paraglider 200 to veer sharply to one side, which may trigger sideslipping or spiral dive. The stalled wing 211 will exhibit stall deformation, descent, and a significant increase in airflow noise.

[0081] refer to Figure 8 , Figure 8A schematic flowchart illustrating a control method for a towed drone 100 according to some embodiments of this application is shown. As described above, the towed drone 100 includes a plurality of vertical rotors 124 and two pull rotors 134. The rotation axis of each pull rotor 134 is a first direction. The towed drone 100 is configured to be connected to a powerless aircraft via a tow rope 400. Figure 8 As shown, the control method includes the following steps.

[0082] Step S10: Obtain the preset flight direction of the unpowered aircraft.

[0083] Taking the paraglider 200 as an example of a non-powered aircraft, the user can manually set the preset flight direction of the paraglider 200 through the control station 300. The user can comprehensively consider the takeoff point of the paraglider 200, real-time wind direction and speed information, updraft information, no-fly zones, dangerous obstacles, etc., to set the preset flight direction of the paraglider 200. This preset flight direction can then be input or transmitted to the towing drone 100.

[0084] refer to Figure 9 , Figure 9 The diagram illustrates an implementation of a control method according to some embodiments of this application. Since the towing drone 100 is generally used to assist the paraglider 200 in its ascent, the preset flight direction generally refers to the takeoff flight direction FD of the paraglider 200. During the flight of the paraglider 200, the paraglider 200 operator can generally change the specific flight direction of the paraglider 200 in real time according to the specific situation and personal preference.

[0085] Step S20: Control the towing drone 100 to move to the front and above of the unpowered aircraft along the preset flight direction.

[0086] Taking the paraglider 200 as an example of a non-powered aircraft, such as Figure 9 As shown, the towing drone 100 can automatically, or under the control of a drone pilot, fly to a position directly above and in front of the paraglider 200 along a preset flight direction. That is, from the location of the paraglider 200 looking in the preset flight direction, the towing drone 100 flies to a position directly above and in front of the paraglider 200. In some embodiments, the towing drone 100 may then hover at this position, waiting for the paraglider 200 to take off.

[0087] The tow rope 400 of the towing drone 100 can be connected to the tow rope connection mechanism of the paraglider 200 before or after the drone takes off, and this application does not impose any specific restrictions on this.

[0088] In some embodiments, when the towing drone 100 is hovering and the tow rope 400 is connected to the tow rope 400 connection mechanism of the paraglider 200, the direction of the tow rope 400 may be approximately parallel to the first direction of the pull rotor. Approximately parallel means that the angle between the direction of the tow rope 400 and the first direction of the pull rotor is within a threshold range. This threshold range is, for example, ±1°, ±3°, or ±5°. Due to the influence of gravity, the tow rope 400 may have an overall arc shape with a downward sag in the middle, and the degree of sag varies with the tension on the tow rope 400. To facilitate determining the direction of the tow rope 400, the direction of the tow rope 400 may, for example, be characterized as a line connecting a specific point on the towing drone 100 and a specific point on the paraglider 200. For example, the direction of the tow rope 400 may be characterized as a line connecting one end of the tow rope 400 connected to the drone and the other end of the tow rope 400 connected to the paraglider 200. Alternatively, in the case where the traction assembly 150 of the towing drone 100 includes a guide rod 154, the direction of the traction rope 400 can also be characterized, for example, as the direction of the guide rod 154 rotating with the traction rope 400.

[0089] Step S30: Control the towing drone 100 to pull the unpowered aircraft up to the preset altitude via the towing rope 400.

[0090] Taking the paraglider 200 as an example of a non-powered aircraft, the towing drone 100 can pull the paraglider 200 to a preset altitude via the towing rope 400 connecting mechanism connected to the paraglider 200. This preset altitude can be, for example, the cruising altitude of the paraglider 200 or other altitudes; this application does not limit this. Through the towing of the drone 100, the paraglider 200 can quickly ascend to its cruising altitude, shortening the takeoff distance, reducing the requirements for the takeoff site, and lowering the risks during takeoff, thus greatly expanding the adaptable terrain for paragliding 200.

[0091] In some embodiments, the stage in which the controlled traction drone 100 pulls the unpowered aircraft to a preset altitude via the traction rope 400 can be referred to as the traction climb process or climb process of the paraglider 200.

[0092] In some embodiments, the traction climb process of the paraglider 200 may include a first stage, a second stage, and a third stage. The first stage is also called the rapid takeoff stage. The second stage is also called the steady climb stage. The third stage is also called the pre-disengagement stage. The climb rate in the second stage may be less than the climb rate in the first stage. The climb rate in the third stage may be less than the climb rate in the second stage. Climb rate is the height gained per unit time.

[0093] Specifically, in the first stage, namely the rapid ascent stage, the paraglider 200, under its own lift and the traction of the towing drone 100, ascends to a first altitude at a relatively fast first climb rate. This first climb rate is, for example, greater than or equal to 5 meters per second. By towing the paraglider 200 to a high climb rate to the first altitude, the paraglider 200 can quickly escape the influence of ground turbulence or ground obstacles, increasing its maneuverability and reducing the risk of loss of control or collision. This first altitude is, for example, greater than or equal to 30 meters, or for example, greater than or equal to 50 meters, to escape areas strongly affected by ground turbulence. Ground turbulence refers to the irregular and disordered movement of near-ground airflow caused by factors such as ground roughness, terrain undulations, and thermal differences.

[0094] Specifically, in the second phase, namely the steady ascent phase, the paraglider 200 ascends to a second altitude at a second ascent rate range lower than the first ascent rate range. The second altitude may be less than, but close to, the preset altitude described above. As an example, and not a limitation, the second altitude may, for instance, be 20 meters lower than the preset altitude.

[0095] Specifically, in the third stage, namely the pre-departure stage, the paraglider 200 ascends to the preset altitude more slowly at a third climb rate range, which is lower than the second climb rate range. The third climb rate range may, for example, be less than 1 meter per second. Optionally, in the third stage, as the altitude of the paraglider 200 gets closer and closer to the preset altitude, the climb rate of the paraglider 200 may decrease further and further.

[0096] In other embodiments, the paraglider 200 may remain in the stable climb phase described above throughout the entire traction climb phase. That is, the paraglider 200 ascends to a preset altitude at a second climb rate range.

[0097] In some embodiments, the process of controlling the towing drone 100 to pull the unpowered aircraft to a preset height via the towing rope 400, i.e., the towing and climbing phase of the paraglider 200 described above, may include: controlling the towing drone 100 to be positioned higher than the unpowered aircraft, and the height difference HD between the two being (e.g., Figure 9 (As shown) within a first range. The first range is determined by a lower limit and an upper limit. The lower limit of the first range can be, for example, any value between 5 meters and 10 meters, such as 5 meters, 7 meters, 10 meters, etc. The lower limit of the first range can be, for example, any value between 15 meters and 25 meters, such as 15 meters, 18 meters, 20 meters, 25 meters, etc. For example, the height difference HD between the towing drone 100 and the paraglider 200 can be, for example, within the range of 10 meters to 20 meters.

[0098] In some embodiments, when the altitude difference between the unpowered aircraft and the towed drone 100 is within a first range, the angular deviation between the direction of the tow rope 400 and the first direction is less than a first threshold. The first threshold may be, for example, 5°, 3°, or 1°. This first threshold can be set by the user, and this application does not impose specific limitations on it.

[0099] In some embodiments, during the second phase described above, the so-called stable climb phase, the position of the controlled towed drone 100 is higher than that of the unpowered aircraft, and the altitude difference HD between the two is within a first range. The monitoring sensor 520 and processor 610 of the towed drone 100 are configured to acquire the altitude difference HD between the towed drone 100 and the paraglider 200.

[0100] In some embodiments, the step of controlling the position of the towing drone 100 above the unpowered aircraft, and the altitude difference HD between the two being within a first range, includes: in response to the altitude difference HD decreasing below the first range, reducing the ratio of the rotational speed of the pull rotor 134 to the rotational speed of the vertical rotor 124; and / or in response to the altitude difference HD increasing above the first range, increasing the ratio of the rotational speed of the pull rotor 134 to the rotational speed of the vertical rotor 124.

[0101] Specifically, in response to the altitude difference HD decreasing below a first range, the rotational speed of the vertical rotor 124 of the towing drone 100 can be increased for a period of time to enhance the lift of the towing drone 100 and increase the altitude difference HD back to the first range. Here, controlling the towing drone 100 to increase the rotational speed of the vertical rotor 124 is primarily used to enhance the lift of the towing drone 100, restoring the altitude difference HD between the towing drone 100 and the paraglider 200 to the preset first range. Since increasing the rotational speed of the vertical rotor 124 of the towing drone 100 may increase the force on the tow rope 400 while enhancing the lift of the towing drone 100, to prevent fluctuations in the force on the tow rope 400, the rotational speed of the towing drone 100's tension rotor 134 can be simultaneously reduced to avoid drastic fluctuations in the traction force on the paraglider 200. Such drastic fluctuations can affect the safety of the paraglider 200 and the experience of the paraglider operator.

[0102] Specifically, the difference between the height difference HD and the first range can be determined; the increase in the rotational speed of the vertical rotor 124 can be determined based on the difference, so as to restore the height difference HD to the first range within a certain period of time; the decrease in the rotational speed of the tension rotor 134 can be determined based on the increase in the rotational speed of the vertical rotor 124, so as to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0103] In some embodiments, the rotational speed of the vertical rotor 124 may be gradually increased while the rotational speed of the tension rotor 134 may be gradually decreased, so as to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0104] Specifically, in response to the altitude difference HD rising above a first range, the towing drone 100 can be controlled to reduce the rotational speed of its vertical rotor 124 for a period of time to reduce the lift of the towing drone 100 and bring the altitude difference HD back to the first range. Here, controlling the towing drone 100 to reduce the rotational speed of its vertical rotor 124 is mainly used to reduce the lift of the towing drone 100, so as to restore the altitude difference HD between the towing drone 100 and the paraglider 200 to the preset first range. Since reducing the rotational speed of the vertical rotor 124 of the towing drone 100 may reduce the force on the tow rope 400 when reducing the lift of the towing drone 100, in order to prevent fluctuations in the force on the tow rope 400, the towing drone 100 can be simultaneously controlled to increase the rotational speed of its tension rotor 134 to avoid drastic fluctuations in the traction force on the paraglider 200. Such drastic fluctuations can affect the safety of the paraglider 200 and the experience of the paraglider operator.

[0105] Specifically, the difference between the height difference HD and the first range can be determined; the decrease in the rotational speed of the vertical rotor 124 can be determined based on the difference to restore the height difference HD to the first range within a certain time; the increase in the rotational speed of the tension rotor 134 can be determined based on the decrease in the rotational speed of the vertical rotor 124 to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0106] In some embodiments, reference Figure 14 , Figure 14 A schematic diagram showing the relationship between the first included angle θ1 and the second included angle θ2 is provided. The first included angle θ1 is the angle between the first direction D1 (i.e., the rotation axis of the pulling rotor) and the sea level. The second included angle θ2 is the angle between the direction of the traction rope 400 and the sea level. The process of controlling the towing drone 100 to pull the unpowered aircraft to a preset altitude via the traction rope 400, i.e., the towing and climbing phase of the paraglider 200 mentioned above, may include controlling the angle between the first direction D1 and the direction D2 of the traction rope within a preset angle range. This preset angle range may be less than or equal to 20°, less than or equal to 15°, or less than or equal to 10°.

[0107] In some embodiments, during the second phase described above, the so-called stable climb phase, the position of the towed drone 100 is controlled to be higher than that of the unpowered aircraft, while the angle between the first direction D1 and the direction D2 of the tow rope is controlled to be less than or equal to 20°, or less than or equal to 15°, or less than or equal to 10°, or less than or equal to 5°. The monitoring sensor 520 and processor 610 of the towed drone 100 may be configured to acquire this angle. The towed drone 100 may be configured with an angle sensor to detect the direction of the tow rope 400.

[0108] The step of controlling the angle between the first direction D1 and the direction D2 of the traction rope 400 within a preset angle range may include: responding to the angle being greater than the preset angle range, and the first included angle θ1 being greater than the second included angle θ2. In this case, the second included angle θ2 of the traction rope is too small, reducing the ratio of the rotational speed of the tension rotor 134 to the rotational speed of the vertical rotor 124; and / or, responding to the angle being greater than the preset angle range, and the first included angle θ1 being less than the second included angle θ2, increasing the ratio of the rotational speed of the tension rotor 134 to the rotational speed of the vertical rotor 124.

[0109] Specifically, in response to the angle being greater than a preset angle range, and the first included angle θ1 being greater than the second included angle θ2, the rotational speed of the vertical rotor 124 of the towing drone 100 can be increased for a period of time to increase the lift of the towing drone 100 and reduce the angle to less than or equal to 20°. Here, controlling the towing drone 100 to increase the rotational speed of the vertical rotor 124 is mainly used to increase the lift of the towing drone 100 to restore the angle between the towing drone 100 and the paraglider 200 to the preset angle range. Since increasing the rotational speed of the vertical rotor 124 of the towing drone 100 may increase the force on the tow rope 400 when increasing the lift of the towing drone 100, in order to prevent fluctuations in the force on the tow rope 400, the rotational speed of the towing drone 100's tension rotor 134 can be reduced simultaneously to avoid drastic fluctuations in the traction force on the paraglider 200. Such drastic fluctuations can affect the safety of the paraglider 200 and the experience of the paraglider operator.

[0110] Specifically, a specific angle can be determined; based on this angle, the increase in the rotational speed of the vertical rotor 124 can be determined to restore the angle to the preset angle range within a certain time; based on the increase in the rotational speed of the vertical rotor 124, the decrease in the rotational speed of the tension rotor 134 can be determined to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0111] In some embodiments, the rotational speed of the vertical rotor 124 may be gradually increased while the rotational speed of the tension rotor 134 may be gradually decreased, so as to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0112] Specifically, in response to the angle being greater than a preset angle range, and the first included angle θ1 being less than the second included angle θ2, the rotational speed of the vertical rotor 124 of the towing drone 100 can be reduced for a period of time to reduce the lift of the towing drone 100 and lower the angle to within the preset angle range. Here, controlling the towing drone 100 to reduce the rotational speed of the vertical rotor 124 is mainly used to reduce the lift of the towing drone 100 to restore the angle between the towing drone 100 and the paraglider 200 to within the preset angle range. Since reducing the rotational speed of the vertical rotor 124 of the towing drone 100 may reduce the force on the tow rope 400 when reducing the lift of the towing drone 100, in order to prevent fluctuations in the force on the tow rope 400, the rotational speed of the pull rotor 134 of the towing drone 100 can be increased simultaneously to avoid drastic fluctuations in the traction force on the paraglider 200. Such drastic fluctuations can affect the safety of the paraglider 200 and the experience of the paraglider operator.

[0113] Specifically, a specific angle can be determined; based on this angle, the amount of reduction in the rotational speed of the vertical rotor 124 can be determined so that the angle can be restored to the preset angle range within a certain period of time; based on the amount of reduction in the rotational speed of the vertical rotor 124, the amount of increase in the rotational speed of the tension rotor 134 can be determined so that the fluctuation of the traction force on the traction rope 400 can be controlled within a safe range.

[0114] In some embodiments, the rotational speed of the vertical rotor 124 may be gradually reduced while the rotational speed of the tension rotor 134 may be gradually increased, so as to control the fluctuation of the traction force on the traction rope 400 within a safe range.

[0115] In some embodiments, the process of controlling the traction drone 100 to pull the unpowered aircraft to a preset height via the traction rope 400 further includes: controlling the first direction to tend to be parallel with the direction of the traction rope 400; and / or controlling the direction of the traction rope 400 to tend to be parallel with the chord of the unpowered aircraft.

[0116] In this application, as described above, the first direction, namely the rotation axis direction of the pull rotor 134, represents the direction of the pull force generated by the rotation. The direction of the traction rope 400 represents the direction of the pull force exerted by the paraglider 200 on the towing drone 100. By controlling the direction of the pull force generated by the pull rotor 134 to be parallel to the direction of the traction rope 400—that is, by adjusting the drone's attitude or the angle of the vertical rotor 124—the direction of the pull force and the reaction force acting on the towing drone 100 through the traction rope 400 can be made to form a collinear force state. This optimizes the mechanical transmission efficiency of the entire traction system 10, improves the energy utilization efficiency of the towing drone 100's battery, thereby reducing the battery weight required for the towing drone 100 and lowering its cost. Furthermore, when the first direction is parallel or approximately parallel to the direction of the towing rope 400, the magnitude of the traction force on the paraglider 200 can be adjusted simply by adjusting the tension of the pull rotor, thereby simplifying the control algorithm of the towing drone 100, allowing the towing drone 100 to adjust its control attitude at a faster speed and with higher precision, and enhancing the reliability and stability of the entire towing system 10.

[0117] As described above, the towed drone 100 may include a guide rod 154 for guiding the tow rope 400. The tow rope 400 may be configured to extend along the guide rod 154 away from the towed drone 100 until it is connected to the paraglider 200. In this case, the operation of controlling the first direction to tend to be parallel with the direction of the tow rope 400 may include: adjusting the attitude of the towed drone 100 until the first direction tends to be parallel with the extension direction of the guide rod 154. For example, the attitude angle of the towed drone 100 may be adjusted until the first direction is parallel to the guide rod 154; or a target attitude angle of the towed drone 100 may be calculated when the first direction of the towed drone 100 is parallel to the current extension direction of the guide rod 154; and the attitude angle of the towed drone 100 may be adjusted to the target attitude angle. The attitude angle adjustment of the towed drone 100 may be achieved by adjusting the lift magnitude of the plurality of vertical rotors 124 of the towed drone 100, which will not be described in detail here. The attitude angle may include roll angle, pitch angle, or yaw angle. In some embodiments, while the pitch angle of the towing drone 100 is less than or equal to 10° or less than or equal to 5°, the first direction is controlled to tend to be parallel to the direction of the towing rope 400. For example, the direction of the towing rope 400 can be adjusted by changing the height of the towing drone 100 while keeping the pitch angle of the towing drone 100 substantially small.

[0118] In this application, the direction of the control traction rope 400 is made parallel to the chord line of the unpowered aircraft. As described above, in the case where the unpowered aircraft is a paraglider 200, the mean aerodynamic chord line is an imaginary straight line from the leading edge to the trailing edge of the airfoil, also referred to as the chord line of the wing 211. In some embodiments, making the direction of the control traction rope 400 parallel to the chord line of the unpowered aircraft includes: determining the chord line direction of the unpowered aircraft based on data collected by the inertial measurement unit of the paraglider 200 or data collected by the monitoring sensor 520 of the towing drone 100; and adjusting the attitude of the towing drone 100 so that the extension direction of the guide rod 154 is parallel to the chord line direction.

[0119] Specifically, the attitude data of the paraglider 200 collected by its inertial measurement unit (IMU) can be used to directly calculate the chord direction of the unpowered aircraft. As an example, and not a limitation, the IMU of the paraglider 200 can be mounted on the ribs 2113 of the wing 211 of the paraglider 200, particularly on the ribs 2113 at both ends of the wing 211, to improve the accuracy of attitude measurement. The IMU may include, for example, a three-axis accelerometer, a three-axis gyroscope, and a magnetometer. The IMU can output the attitude angles of the paraglider 200's wing 211, including roll, pitch, and yaw angles. In some embodiments, a body coordinate system of the paraglider 200 can be established. Figure 7 As shown, in the body coordinate system of paraglider 200, the X-axis represents the longitudinal direction of paraglider 200, the Y-axis represents the vertical direction of paraglider 200, and the Z-axis is perpendicular to the XY plane defined by the X and Y axes, i.e., the lateral direction of paraglider 200. The pitch angle represents the rotation angle of paraglider 200 around the Y-axis. Generally, the pitch angle is positive when paraglider 200 is tilted up and negative when it is tilted down. The yaw angle represents the rotation angle of paraglider 200 around the Z-axis. Generally, the yaw angle is positive when paraglider 200 yaws to the left and negative when it yaws to the right. The roll angle represents the rotation angle of paraglider 200 around the X-axis. The roll angle is positive when paraglider 200 is tilted to the left and negative when it is tilted to the right. The attitude angles can be converted into the direction of the chord of the paraglider 211 through coordinate transformation. The chord direction can be represented as the direction vector of the chord in a specific coordinate system, or it can be represented as the chord pitch angle relative to the horizontal plane and the chord azimuth angle relative to a reference line fixed to the ground. The specific coordinate system can be a geographic coordinate system (a coordinate system fixed to the ground), a body coordinate system fixed to the paraglider 200 (e.g., fixed to the wing rib 2113 of the paraglider 200), or other user-defined coordinate systems.

[0120] When the towing drone 100 tows the paraglider 200, by controlling the direction of the towing rope 400 to be parallel to the chord of the paraglider 200, it is possible to help maintain the chord direction of the paraglider 200 unchanged, reduce the influence of the traction force of the towing rope 400 on the attitude of the paraglider 200, reduce unnecessary attitude adjustment losses during the towing process, increase towing efficiency, and reduce battery consumption of the towing drone 100.

[0121] In some embodiments, by simultaneously controlling the first direction to be parallel to the direction of the traction rope 400 and controlling the direction of the traction rope 400 to be parallel to the chord of the unpowered aircraft, a synergistic effect can be achieved, improving the energy utilization efficiency of the battery of the towed drone 100, thereby reducing the battery weight required for the towed drone 100. At the same time, it allows the towed drone 100 to adjust and control its attitude at a faster speed and with higher precision, reducing the impact of the traction force of the traction rope 400 on the attitude of the paraglider 200, and enhancing the reliability and stability of the entire towing system 10.

[0122] In some embodiments, only in the second stage described above, the first direction is controlled to tend to be parallel to the direction of the traction rope 400, and / or the direction of the traction rope 400 is controlled to tend to be parallel to the chord of the unpowered aircraft.

[0123] refer to Figure 10 , Figure 10 Some embodiments according to this application are shown. Figure 8 A flowchart illustrating step S30 in the process.

[0124] The above discussion primarily focused on the stable climb of the paraglider 200. However, during the climb, the paraglider 200's specific attitude and flight direction are controlled in real-time by the operator. Simultaneously, due to airflow factors such as crosswinds and turbulence, the paraglider 200's flight status may change unexpectedly, even posing a stall risk. To address these anticipated or unexpected changes in the paraglider 200's flight status—that is, to cope with other states besides stable climb—such as… Figure 10 As shown, Figure 8 Step S30, which controls the towing drone 100 to pull the unpowered aircraft to a preset altitude via the towing rope 400, also includes the following operations.

[0125] Operation S610: Obtain the flight status of the unpowered aircraft.

[0126] In some embodiments, taking the paraglider 200 as an example of an unpowered aircraft, the flight state includes at least one of the angle of attack, attitude parameters, and stall state of the paraglider 200. The attitude parameters may include at least one of the pitch angle, yaw angle, roll angle, or chord direction of the paraglider 200 as described above.

[0127] In some embodiments, taking the paraglider 200 as an example of an unpowered aircraft, obtaining the flight status of the unpowered aircraft includes: collecting data of the paraglider 200 through the monitoring sensor 520 of the towing drone 100; and processing the data to obtain the flight status of the paraglider 200.

[0128] In some embodiments, the monitoring sensor 520 includes a camera, such as the RGB gimbal camera described above. The camera may also be, for example, an infrared camera, a depth camera, a grayscale camera, etc., and this application does not impose specific limitations on this. The acquired data of the paraglider 200 includes images of the paraglider 200 captured by the camera. In this case, the attitude parameters of the paraglider 200 can be determined based on the difference between the current image of the paraglider 200 and the reference image of the paraglider 200.

[0129] In actual operation, the specific shooting direction of the camera can change continuously relative to the towing drone 100 body, and the relative distance or relative angle between the towing drone 100 and the paraglider 200 is also constantly changing. Therefore, it is necessary to calibrate at least one reference image to compare with the paraglider 200 image captured by the camera of the towing drone 100 in order to determine the flight status of the paraglider 200.

[0130] In some embodiments, the second direction is defined as a direction perpendicular to the rotation axis of each pull rotor 134. The reference image is an image of the paraglider 200 captured by the camera of the towing drone 100 when the imaging plane of the camera is parallel to the wingspan extension direction of the paraglider 200 and parallel to the second direction. In this case, there is no lateral offset between the towing drone 100 and the paraglider 200. The reference image can be any reference image that satisfies this condition. In this case, the paraglider 200 is presented as a non-tilted, orthographic projection in the reference image, and the paraglider 200 is uniformly distributed in the image, reducing feature distortion caused by perspective distortion.

[0131] Furthermore, in some embodiments, the reference imaging is the image of the paraglider 200 captured by the camera of the towing drone 100 when the imaging plane of the camera is perpendicular to the chord direction of the paraglider 200. In this case, there is no left-right offset between the towing drone 100 and the paraglider 200, and the chord of the paraglider 200 is represented as a series of points in the reference imaging. At this time, the optical axis of the camera is strictly aligned with the chord direction, making it easy to quickly determine the attitude parameters of the paraglider 200 by observing the length and angle of the chord in the current image.

[0132] The current image is the image of the paraglider 200 captured by the camera of the towing drone 100. Optionally, the current image is the image of the paraglider 200 captured by the camera when the optical axis of the towing drone 100's camera is located on the plane of symmetry of the towing drone 100. Further optional, the current image is the image of the paraglider 200 captured by the camera when the optical axis of the towing drone 100's camera is parallel to the first direction. The current image can also be an image captured at other angles along the camera's optical axis, as long as the image can be reasonably and effectively compared with a reference image through post-processing; this application does not impose specific limitations in this regard.

[0133] Both the reference image and the current image can include imaging features. The specific number of imaging features can be set by the user.

[0134] The operation of determining the attitude parameters of the paraglider 200 based on the difference between the current image of the paraglider 200 and the reference image of the paraglider 200 may include: determining the current attitude parameters of the paraglider 200 based on the difference between the imaging features of the current image and the imaging features of the reference image.

[0135] In some embodiments, the reference image may include N pre-labeled imaging features, where N is a positive integer. The imaging features in the reference image are actually two-dimensional projections of the three-dimensionally distributed imaging features on the paraglider 200 onto the reference image; therefore, the imaging features in the reference image can be called reference imaging feature projections. The reference imaging feature projections correspond to the attitude parameters of the paraglider 200 relative to the towing drone 100 when the reference image is generated, and can be called reference attitude parameters. Similarly, the imaging features in the current image are actually two-dimensional projections of the three-dimensionally distributed imaging features on the paraglider 200 onto the current image; therefore, the imaging features in the current image can be called current imaging feature projections. The current imaging feature projections correspond to the current attitude parameters of the paraglider 200 relative to the towing drone 100 when the current image is generated. By comparing the current imaging feature projections and the reference imaging feature projections, the attitude parameter difference between the current attitude parameters and the reference attitude parameters of the paraglider 200 is resolved; by adding the attitude parameter difference to the reference attitude parameters, the current attitude parameters of the paraglider 200 can be obtained.

[0136] In some embodiments, a database of correspondences between the distribution of current imaging feature projections and attitude parameter differences can be pre-established. In this case, the reference imaging feature projection can be used only to assist in identifying the current imaging feature projection. First, the current imaging feature projection in the current image is identified. After identifying the current imaging feature projection and obtaining its distribution, the corresponding attitude parameter difference can be obtained by retrieving the database of correspondences. In some embodiments, a three-dimensional digital model of the paraglider 200 can be established, and the database of correspondences can be established by rotating the three-dimensional digital model and performing simulated projection.

[0137] In some embodiments, the step of comparing the current imaging feature projection and the reference imaging feature projection to parse the attitude parameter difference between the current attitude parameters and the reference attitude parameters of the paraglider 200 may include: identifying the current imaging feature projection in the current imaging; matching the current imaging feature projection and the reference imaging feature projection to generate an element-to-element correspondence between the current imaging feature projection coordinate vector and the reference imaging feature projection vector; and parsing the current imaging feature projection coordinate vector and the reference imaging feature projection vector to obtain the attitude parameter difference.

[0138] Specifically, the following formulas (1)-(3) exist:

[0139] Formula (1): Current imaging feature projection coordinate vector = Current imaging feature 3D coordinate matrix * Projection matrix;

[0140] Formula (2) Reference imaging feature projection vector = Reference imaging feature three-dimensional coordinate matrix * Projection matrix; and,

[0141] Formula (3) Current imaging feature three-dimensional coordinate matrix = Reference imaging feature three-dimensional coordinate matrix * Attitude transformation matrix.

[0142] Wherein, the attitude transformation matrix represents the attitude parameter difference between the current attitude parameters and the reference attitude parameters; the current imaging feature three-dimensional coordinate matrix represents the three-dimensional coordinates of multiple imaging features of the paraglider 200 in a coordinate system at the current imaging moment; the reference imaging feature three-dimensional coordinate matrix represents the three-dimensional coordinates of multiple imaging features of the paraglider 200 in the same coordinate system when shooting the reference image. The projection matrices in formulas (1) and (2) can usually be obtained from the camera parameters. The projection matrices in formulas (1) and (2) can be the same or different. As an example, when the projection matrices in formulas (1) and (2) are the same, combining formulas (1), (2) and (3), the current imaging feature projection coordinate vector = reference imaging feature three-dimensional coordinate matrix * attitude transformation matrix * projection matrix = reference imaging feature projection vector * (projection matrix) T *Attitude transformation matrix*Projection matrix. That is, we can obtain formula (4): Current imaging feature projection coordinate vector = Reference imaging feature projection vector *(Projection matrix) T *Attitude transformation matrix* Projection matrix. Given the projection matrix, the current imaging feature projection coordinate vector, and the reference imaging feature projection vector, the attitude transformation matrix can be solved using formula (4), and the attitude parameter difference corresponding to this matrix can then be obtained. When the projection matrices in formulas (1) and (2) are different but can be obtained from the camera parameters, the attitude transformation matrix can be similarly solved by combining formulas (1), (2), and (3), and the attitude parameter difference corresponding to this matrix can then be obtained. This application will not elaborate further on this point.

[0143] In some embodiments, the current image may be preprocessed before identifying the projection of current imaging features in the current image. Preprocessing may include normalizing, denoising, and enhancing the current image. Normalization may include physically consistent scaling of the current image. For example, the current image corresponds to a camera focal length of f. 当前 The reference imaging corresponds to a camera focal length of f. 参考 Then, during preprocessing, the scaling factor for the current image is S = f. 参考 / f 当前 This scaling operation can be used to compensate for the effect of the camera's focal length on the image. Normalization can also compensate for the distance between the camera and the paraglider 200, but this application does not impose specific limitations on this.

[0144] In some embodiments, the imaging features can be multiple key points of the paraglider 200. The number of key points can be a positive integer, optionally a positive integer greater than or equal to 4. At least one key point of the paraglider 200 may include a leading edge point of the wing rib, a trailing edge point of the wing rib, a parachute line connection point, a center symmetry point, a contour point, etc. The specific number of key points can be set by the user.

[0145] In some embodiments, the imaging features can be calibration features of the paraglider 200. Marking features may include chords, wing ribs 2113, identification patterns on the paraglider 200, outlines, axes of symmetry, etc. Identification patterns may be, for example, color patterns, black and white patterns, text, checkerboard patterns, etc.

[0146] In some embodiments, the imaging feature can be the axis of symmetry of the paraglider 200. The axis of symmetry of the paraglider 200 may include the horizontal axis and the vertical axis of the paraglider 200.

[0147] In some embodiments, the identification of the attitude parameters of the paraglider 200 can also be performed by a neural network model in a neural network processing unit deployed on the towing drone 100, and this application does not impose any specific limitations on this.

[0148] Operation S620: Control the flight mode of the towing UAV 100 based on flight status.

[0149] Through the above operations, this application can obtain the attitude parameters of the paraglider 200 in order to adjust the flight mode of the towing drone 100 accordingly.

[0150] For example, if the acquired attitude parameters indicate that the paraglider 200 is in a flight state that is deflected to one side, the flight mode of the towing drone 100 can be controlled to deflect to the same side accordingly, so as to ensure that the towing drone 100 performs the towing operation directly in front of and above the paraglider 200. For example, when the paraglider 200 is detected to be deflecting to the right, the speed of the vertical rotor 124 of the towing drone 100 is adjusted to control the towing drone 100 to deflect to the right, so that the heading of the towing drone 100 tends to be parallel to the heading of the paraglider 200; when the paraglider 200 is detected to be deflecting to the left, the speed of the vertical rotor 124 of the towing drone 100 is adjusted to control the towing drone 100 to deflect to the left, so that the heading of the towing drone 100 tends to be parallel to the heading of the paraglider 200.

[0151] In some embodiments, if the acquired attitude parameters indicate that the flight state of the paraglider 200 is a change in the chord direction, the flight mode of the towing drone 100 can be controlled to change the pitch angle so that the guide rod 154 of the towing drone 100 tends to be parallel to the chord of the paraglider 200.

[0152] In some embodiments, to address the risk of paraglider 200 stall, refer to Figure 11 , Figure 11 Other embodiments according to this application are shown. Figure 8 The flowchart of step S30 is shown below. In the case where the unpowered aircraft is a paraglider 200, the operation of obtaining the flight status of the unpowered aircraft in operation S610 may include the following operations.

[0153] Operation S710: Acquire at least one of the following: an image of the paraglider 200 wing 211, the yaw acceleration of the wing 211, the airflow sound on the upper surface of the wing 211, and the angle of attack of the wing 211.

[0154] In some embodiments, images of the wing 211 of the paraglider 200 can be acquired through the monitoring sensor 520 of the towing drone 100 described above, or the deflection acceleration of the wing 211 can be acquired through the paraglider IMU 530 component described above, or the airflow sound of the upper surface of the wing 211 can be collected through a microphone deployed on the wing 211 of the paraglider 200, or the angle of attack of the wing 211 can be determined by the collected chord direction and airflow direction of the paraglider 200.

[0155] S720: In response to at least one or more of the following conditions, determine that the paraglider 200 has entered a stall state: stall deformation of the paraglider 211 is identified in an image of the paraglider 211; the yaw acceleration of the paraglider 211 exceeds a stall acceleration threshold; the angle of attack of the paraglider 211 exceeds a stall angle of attack threshold; or stall sound features are identified in the airflow sound on the upper surface of the paraglider 211.

[0156] In some embodiments, step S720 may include: identifying stall deformation or stall sound characteristics of the parachute 211 using a neural network model deployed on the towing drone 100.

[0157] A neural network model can be deployed on the onboard processing unit 510 as described above. The neural network model can be trained using images including stall deformation as a training set, and the trained neural network model can be configured to recognize stall deformation of the paraglider 211 from images of the paraglider 211. The neural network model can also be trained using audio including the sound of airflow over the upper surface of the paraglider 211 during stall as a training set, and the trained neural network model can be configured to recognize stall sound features of the paraglider 211. Sound acquisition devices such as microphones can be deployed on the paraglider 211, and the acquired audio is sent to the towing drone 100 for identifying stall sound features. When stall sound features are identified in the airflow over the upper surface of the paraglider 211, it can be determined that the paraglider 200 has entered a stall state. In some embodiments, images of the paraglider 211 or acquired audio can be sent to a control station 300 or a cloud server 700, which can identify stall deformation or stall sound features.

[0158] Specifically, the camera of the towing drone 100 can capture images of the paraglider 211, which can then be used by the towing drone 100, control station 300, or cloud server 700 to identify stall deformation of the paraglider 211. Stall deformation may include collapse, folding, wrinkling, or cave-in of the upper wing surface 2111 of the paraglider 211. Stall deformation can occur in a localized area or a large area of ​​the paraglider 211. When stall deformation of the paraglider 211 is detected in the image of the paraglider 211, it can be determined that the paraglider 200 has entered a stall state.

[0159] The paraglider IMU 530 component of wing 211 can detect the yaw acceleration of wing 211 and send it to the towing drone 100, control station 300, or cloud server 700 to detect whether the yaw acceleration exceeds a threshold. When the yaw acceleration of wing 211 exceeds the stall acceleration threshold, it can be determined that the paraglider 200 has entered a stall state.

[0160] In some embodiments, the paraglider IMU 530 assembly of the paraglider 211 can monitor the chord direction of the paraglider 211, or can identify the current image acquired by the towing drone 100 as described above to obtain the chord direction of the paraglider 211. As described above, the angle of attack is the angle θ between the average aerodynamic chord of the paraglider 200 and the relative airflow direction. Instruments mounted on the paraglider 200 can acquire the relative airflow direction and further combine it with the chord direction to determine the angle of attack of the paraglider 200. When the angle of attack of the paraglider 211 exceeds the stall angle of attack threshold, it can be determined that the paraglider 200 has entered a stall state.

[0161] In some embodiments, operation S620 further includes S730: in response to determining that the paraglider 200 has entered a stall state, controlling the towing drone 100 to enter a stall recovery mode. In the stall recovery mode, the towing drone 100 can perform stall recovery operations to assist the paraglider 200 in recovering from the stall state, thereby reducing the risk to the paraglider 200 and / or the paraglider 200 operator.

[0162] In some embodiments, the stall recovery mode includes at least one of the following: the towing drone 100 in a dive state; the towing drone 100's pull rotor 134 increasing its rotational speed; the towing rotor 134's rotational speed fluctuating periodically; or the towing rope 400 retracting.

[0163] Stall recovery mode may include the towing drone 100 in a dive state. In stall recovery mode, the towing drone 100 may actively dive diagonally downwards, causing the paraglider 200 to reduce its angle of attack and increase its speed, so as to restore the airflow velocity on the upper wing surface 2111 of the paraglider 211 and help the paraglider 200 recover from the stall quickly.

[0164] The stall recovery mode may include increasing the rotational speed of the pull rotor 134 of the towing drone 100. In this mode, the towing drone 100 can rapidly increase the pull on the paraglider 200 by increasing the rotational speed of the pull rotor 134, thereby reducing the oscillation of the paraglider 200 caused by the turbulent airflow experienced by the paraglider 200 during a stall.

[0165] Stall recovery modes may include periodic fluctuations in the rotational speed of the thrust rotor 134, producing an effect similar to flutter recovery. For example, the towing drone 100 may alternately increase and decrease the thrust in a cycle of 0.5-1 seconds, causing the paraglider 200 to produce small pitch oscillations, prompting the airflow to reattach to the wing surface of the paraglider 211, thus helping the paraglider 200 recover from a stall.

[0166] The stall recovery mode may include the retraction of the tow rope 400. In this mode, the towing drone 100 can quickly retract the tow rope 400 to enhance the power coupling between the towing drone 100 and the paraglider 200, directly dragging the paraglider 200 to recover from the stall.

[0167] The stall recovery mode of the towing drone 100 can be intelligently or automatically triggered by the controller or console of the towing drone 100 to achieve rapid response.

[0168] After the paraglider 200 recovers from a stall, the towing drone 100 can adjust its attitude or restore the length of the tow rope 400 to continue towing the paraglider 200 for a stable ascent. Alternatively, the tow rope 400 can be cut from the paraglider 200 to allow it to find an opportunity to land on its own.

[0169] Stall handling is a core challenge in paragliding 200 pilot training, posing a significant learning curve, especially for beginners. This application overcomes the bottlenecks of traditional training by real-time monitoring of the paraglider 200's stall status and triggering an intelligent recovery mechanism on the towing drone 100. This technical solution not only significantly reduces the technical difficulty of stall handling but also substantially reduces equipment damage and personnel safety risks caused by operational errors through automated safety protection. This solution effectively lowers the entry barrier for paragliding 200, helping to promote the sport from a professional circle to widespread public participation.

[0170] In some embodiments, reference Figure 12 , Figure 12 A schematic flowchart illustrating a control method for a towed drone 100 according to other embodiments of this application is shown. (See reference...) Figure 8 and Figure 12 The control method may also include step S40: in response to the unpowered aircraft ascending to a preset altitude, disconnecting the connection between the traction rope 400 and the unpowered aircraft.

[0171] Specifically, the paraglider 200 operator or the control station 300 operator can send a detachment command to safely separate the tow rope 400 from the paraglider 200. This application does not limit the specific method of separation between the tow rope 400 and the paraglider 200.

[0172] The towed drone 100 can then return to its home base and land. The towed drone 100 can return to its home base under the control of the pilot or automatically.

[0173] The towing method described in this application significantly reduces the takeoff time of the paraglider 200 to just a few minutes. Compared to traditional takeoff methods that rely on natural airflow, the technical solution of this application overcomes the limitations of weather conditions or terrain, significantly improving the safety of the paraglider 200 during takeoff and facilitating its promotion in more regions and climates. Furthermore, by increasing the towing efficiency of the towing drone 100 on the unpowered aircraft, the technical solution of this application reduces its battery capacity requirements and costs, further lowering the cost of paragliding and contributing to its wider adoption.

[0174] refer to Figure 13 , Figure 13 A schematic diagram of the structure of a control system 600 according to some embodiments of this application is shown. Figure 13 As shown, the control system 600 includes a processor 610 and a memory 620. The memory 620 stores program code. The processor 610 is configured to execute the program code to implement the above-mentioned reference. Figure 8 and Figures 10-12Any of the methods described herein are further detailed in the foregoing description and will not be repeated here. The processor 610 may include one or more processors 610 deployed in the towing drone 100, control station 300, or cloud server 700. The memory 620 may also include one or more memories 620 deployed in the towing drone 100, control station 300, or cloud server 700. No limitations are imposed in this application.

[0175] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0176] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus implementations described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of the apparatus or units may be electrical, mechanical, or other forms.

[0177] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

Claims

1. A control method for a towed unmanned aerial vehicle (UAV), the UAV comprising multiple vertical rotors and two pull rotors, each pull rotor having its rotation axis in a first direction, the UAV configured to be connected to a powerless aircraft via a tow rope, characterized in that, The method includes: Obtain the preset flight direction of the unpowered aircraft; Control the towing drone to move to the front and above the unpowered aircraft along the preset flight direction; and The system controls the towing drone to pull the unpowered aircraft to a preset altitude via the towing rope. The control of the traction drone to pull the unpowered aircraft to a preset height via the traction rope includes: When the unpowered aircraft is climbing, the angle between the first direction and the direction of the traction rope is controlled to be less than or equal to 20°.

2. The method according to claim 1, characterized in that, Also includes: The step of controlling the angle between the first direction and the direction of the traction rope to be less than 20° includes: In response to the angle being greater than 20°, and the first angle between the first direction and the sea level being greater than the second angle between the direction of the traction rope and the sea level, the ratio of the rotational speed of the tension rotor to the rotational speed of the vertical rotor is reduced; and / or In response to the angle being greater than 20° and the first included angle being less than the second included angle, the ratio of the rotational speed of the thrust rotor to the rotational speed of the vertical rotor is increased.

3. The method according to claim 1, characterized in that, The method of controlling the traction drone to pull the unpowered aircraft to a preset altitude via the traction rope also includes: Controlling the first direction to be parallel to the direction of the traction rope; and / or The direction of the traction rope is controlled to be parallel to the chord of the unpowered aircraft.

4. The method according to claim 3, characterized in that, The method of controlling the traction drone to pull the unpowered aircraft to a preset altitude via the traction rope also includes: While the pitch angle of the towing drone is less than or equal to 5°, the first direction is controlled to tend to be parallel to the direction of the towing rope.

5. The method according to claim 3, characterized in that, The towing drone includes a guide rod for guiding the towing rope, the towing rope being configured to extend along the guide rod away from the towing drone to connect to the unpowered aircraft; The control of making the first direction parallel to the direction of the traction rope includes: Adjust the attitude of the towing drone until the first direction is nearly parallel to the extension direction of the guide rod; and / or The control of the direction of the traction rope to be parallel to the chord of the unpowered aircraft includes: Based on data collected by the inertial measurement unit of the unpowered aircraft or data collected by the monitoring sensors of the towed drone, the chord direction of the unpowered aircraft is determined; and Adjust the attitude of the traction drone until the extension direction of the guide rod is parallel to the chord.

6. The method according to claim 3, characterized in that, The process of the unpowered aircraft ascending to the preset altitude includes a first stage and a second stage in sequence, and the climb rate of the unpowered aircraft in the second stage is greater than the climb rate of the unpowered aircraft in the first stage. and The control of making the first direction parallel to the direction of the traction rope includes: In the second stage, the first direction is controlled to tend to be parallel to the direction of the traction rope; and / or The control of the direction of the traction rope to be parallel to the chord of the unpowered aircraft includes: In the second stage, the direction of the traction rope is controlled to be parallel to the chord of the unpowered aircraft.

7. The method according to claim 1, characterized in that, The towing drone includes a towing arm, one end of which is connected to the middle of the towing arm, and two towing rotors are symmetrically fixed on both sides of the middle of the towing arm. The center of gravity of the towing drone is located at the middle of the pulling arm.

8. The method according to claim 1, characterized in that, The method of controlling the traction drone to pull the unpowered aircraft to a preset altitude via the traction rope also includes: Obtain the flight status of the unpowered aircraft; and The flight mode of the towing drone is controlled based on the flight status; The flight state includes at least one of the angle of attack, attitude parameters, and stall state of the unpowered aircraft.

9. The method according to claim 7, characterized in that, The unpowered aircraft is a paraglider; The process of obtaining the flight status of the unpowered aircraft includes: The paraglider's data is collected by the monitoring sensors of the towing drone; Process the data to obtain the flight status of the paraglider; and / or The process of obtaining the flight status of the unpowered aircraft includes: The flight status of the paraglider is determined based on data collected by its inertial measurement unit and / or sensors.

10. The method according to claim 9, characterized in that, The monitoring sensor includes a camera, and the data collected from the paraglider includes images of the paraglider captured by the camera; The process of processing the data to obtain the flight status of the paraglider includes: Based on the difference between the current image of the paraglider and the reference image of the paraglider, the attitude parameters of the paraglider are determined. The attitude parameters include the paraglider's pitch angle, yaw angle, roll angle, or chord direction.

11. The method according to claim 10, characterized in that, The step of determining the attitude parameters of the paraglider based on the difference between the current image of the paraglider and the reference image of the paraglider includes: determining the current attitude parameters of the paraglider based on the difference between the imaging features of the current image and the imaging features of the reference image. The imaging features include at least one of the following: at least one key point of the paraglider, at least one calibration feature of the paraglider, the outline of the paraglider, or the axis of symmetry of the paraglider.

12. The method according to claim 10, characterized in that, The second direction is perpendicular to the rotation axis of each tension rotor; The reference imaging refers to the image of the paraglider captured by the camera when the imaging plane of the camera is parallel to the extension direction of the paraglider's wingspan and parallel to the second direction.

13. The method according to claim 11, characterized in that, The reference imaging refers to the image of the paraglider captured by the camera when the imaging plane of the camera is perpendicular to the chord direction of the paraglider.

14. The method according to claim 8, characterized in that, The unpowered aircraft is a paraglider; The process of obtaining the flight status of the unpowered aircraft includes: Acquire at least one of the following: an image of the paraglider's wing, the yaw acceleration of the wing, the airflow sound on the upper surface of the wing, and the angle of attack of the wing; The paraglider is determined to have entered a stall state in response to at least one or more of the following conditions: Stall deformation of the parachute wing was identified in the image of the parachute wing; The deflection acceleration of the parachute exceeds the stall acceleration threshold; The angle of attack of the parachute exceeds the stall angle of attack threshold; or Stall sound characteristics were identified in the airflow sound on the upper surface of the parachute.

15. The method according to claim 14, characterized in that, The determination that the paraglider has entered a stall state is made in response to at least one or more of the following conditions: The stall deformation of the parachute or the stall sound characteristics are identified by a neural network model deployed on the traction drone.

16. The method according to claim 14, characterized in that, The flight mode for controlling the towing UAV based on the flight state includes: In response to determining that the paraglider has entered a stall state, the towing drone is controlled to enter a stall recovery mode; The stall recovery mode includes at least one of the following: The towing drone is in a dive state; the towing drone's pull rotor increases its rotation speed; the pull rotor's rotation speed fluctuates periodically; or the towing rope contracts.

17. The method according to claim 1, characterized in that, In response to the unpowered aircraft ascending to the preset altitude, the connection between the traction rope and the unpowered aircraft is disconnected.

18. A control system, characterized in that, The control system includes a processor and a memory, the memory storing program code, and the processor being configured to execute the program code to implement the method as claimed in claims 1-17.

19. A traction system comprising a traction drone and a powerless aircraft interconnected in communication, characterized in that, The towing drone includes multiple vertical rotors and two pull rotors, the towing drone is configured to be connected to the unpowered aircraft via a towing rope, and the towing drone includes monitoring sensors configured to monitor the unpowered aircraft. The traction system is configured to implement the method as described in claims 1-17.

20. The traction system according to claim 19, characterized in that, The traction system also includes a control station, which is communicatively connected to at least one of the traction drone and the unpowered aircraft.

Images