Strong wind-resistant control method, system, device and medium for tethered unmanned aerial vehicle

Abstract

The application discloses a kind of tethered unmanned aerial vehicle strong wind-resistant control method, system, equipment and medium, comprising: when according to position data determination tethered unmanned aerial vehicle moves to the inside of cable auxiliary wind-resistant region, control enters emergency control mode;When according to position data determination tethered unmanned aerial vehicle moves to the outside of cable auxiliary wind-resistant region, control enters normal control mode;Based on real-time state data and the disturbance estimation value determined by nonlinear disturbance observer exceeds disturbance threshold value, according to disturbance estimation value, original expected trajectory data and impedance controller calculates target expected trajectory data generation control instruction and controls.The application in normal control mode, small disturbance is autonomously adjusted attitude and thrust to realize anti-interference hovering;Disturbance exceeds threshold value, then guide unmanned aerial vehicle to enter cable auxiliary wind-resistant region;Emergency control mode, introduce cable tension as intermediate control variable to realize cable and rotor collaborative anti-interference, significantly improve the ability of stable hovering and operation reliability in complex wind field.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) control technology, and in particular to a control method, system, device, and medium for tethered UAVs with strong wind resistance. Background Technology

[0002] With the rapid development of UAV technology, tethered UAVs are widely used in maritime monitoring, emergency rescue, and other fields due to their continuous power supply, long-term loitering, and stable communication. Connecting a tethered UAV to a ground platform via a cable ensures a continuous power supply while enabling stable hovering for extended periods, providing reliable aerial support for mission execution. In the low-altitude region, wind fields change drastically, with frequent unpredictable aerodynamic disturbances such as gusts and turbulence, posing significant challenges to the attitude stability and position-keeping capabilities of tethered UAVs. Furthermore, the introduction of the cable introduces typical rigid-flexible coupling characteristics into the system, significantly increasing the complexity of the system's dynamics.

[0003] Existing research typically employs robust control, adaptive control, or disturbance observation methods to significantly improve the wind resistance of UAVs. However, these methods are all designed with a single control mode, relying on rotor thrust and attitude adjustment for stable control. When external wind disturbances are strong, relying solely on fixed control strategies can easily lead to decreased control performance or even system instability. Although cable tension can provide auxiliary disturbance suppression, it is treated as a passive constraint, lacking effective utilization of the synergistic relationship between its rotor thrust and the control mechanism.

[0004] Therefore, there is an urgent need for a method that can ensure control accuracy in a weak disturbance environment, enhance system robustness under strong wind disturbance conditions, and effectively utilize the synergistic effect of cable tension and rotor thrust, thereby significantly improving the wind resistance capability of tethered UAVs in complex wind fields to ensure stable hovering and operational reliability.

[0005] A wind-resistant control method that adapts to different modes under different wind disturbance conditions, and simultaneously achieves the synergistic effect of cable tension and rotor thrust, thereby improving the stable hovering capability and operational reliability of tethered UAVs in complex wind fields. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of existing technologies in terms of poor stable hovering ability and poor operational reliability of tethered drones in complex wind fields, and to provide a control method, system, device and medium for tethered drones with strong wind resistance.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution: In a first aspect, the present invention provides a control method for a tethered unmanned aerial vehicle (UAV) with strong wind resistance, the control method comprising: Acquire the original desired trajectory data, real-time status data, and the set tethered wind-resistant zone of the tethered drone; the real-time status data includes position data, velocity data, attitude angle data, and angular velocity data; the tethered wind-resistant zone is used to characterize the spatial range in which the tethered drone maintains safe flight under the combined action of rotor thrust and tether tension; When the location data determines that the tethered drone has moved into the cable-assisted wind-resistant area, the tethered drone is controlled to enter the emergency control mode; the emergency control mode is used to characterize the mode of activating the coordination solver to incorporate cable tension into the intermediate control quantity to achieve coordinated anti-disturbance control of rotor thrust and cable tension; When the location data determines that the tethered drone has moved outside the cable-assisted wind-resistant area, the tethered drone is controlled to enter the normal control mode; the normal control mode is used to characterize the mode in which the normal solver is activated to achieve hovering control by relying on rotor thrust and attitude adjustment; The disturbance estimate is determined based on the real-time state data and the nonlinear disturbance observer. If the disturbance estimate exceeds the disturbance threshold, target desired trajectory data is calculated based on the disturbance estimate, the original desired trajectory data, and the impedance controller, so as to generate control commands to control the tethered UAV based on the target desired trajectory data.

[0008] Preferably, the step of calculating the target desired trajectory data based on the disturbance estimate, the original desired trajectory data, and the impedance controller includes: The position adjustment amount is calculated based on the disturbance estimate and the impedance controller; The target expected trajectory data is calculated based on the original expected trajectory data and the position adjustment amount.

[0009] Preferably, the impedance controller obtains the position adjustment amount based on the disturbance estimate and calculation using a set mass damping stiffness dynamic model; The mathematical expression for the mass-damped stiffness dynamics model is: ; in, This represents the virtual mass matrix, used to characterize the system's inertial response to disturbances. This represents the virtual damping matrix, used to adjust the convergence speed of the system and suppress oscillations; This represents the virtual stiffness matrix, used to determine the mapping relationship between position offset and disturbance; Indicates the amount of position adjustment.

[0010] Preferably, the mathematical expression of the coordinated solver is: ; in, This indicates the cable tension required to tether the drone. express The three-axis components; This indicates the three-axis output of the position loop controller; This represents the desired roll angle, desired pitch angle, and desired yaw angle. Given from the outside; This represents the total lift per unit mass. Indicates the azimuth angle of the cable tension; It represents the acceleration due to gravity.

[0011] Preferably, the control method includes: If the disturbance estimate does not exceed the disturbance threshold, control commands are generated based on the original expected trajectory data to control the tethered drone.

[0012] Preferably, the control method further includes: A dynamic model of the tethered unmanned aerial vehicle system is established; the dynamic model includes an attitude dynamic model and a tethered cable dynamic model. The rope-assisted wind-resistant area is determined based on the posture dynamics model and the mooring rope dynamics model. The pose dynamics model is used to determine the relationship between the three-axis position, velocity and attitude angle in the inertial coordinate system. The tethered cable dynamic model is used to discretize the cable into multiple micro-elements, and determine the motion relationship of each micro-element based on the mass of each micro-element, air resistance, and tension of adjacent micro-elements. The mathematical expression for the rope-assisted wind-resistant zone is: ; This indicates the horizontal distance between the tethered ground platform and the tethered drone; Indicates the altitude of the tethered drone relative to the tethered ground platform; This indicates the maximum length of the rope or cable.

[0013] Preferably, the control method further includes: An anti-interference hovering controller for a tethered unmanned aerial vehicle (UAV) system is established; the anti-interference hovering controller includes a position controller, a control variable solver, and an attitude controller; the control variable solver includes a conventional solver and a coordinated solver. An impedance position planner for a tethered unmanned aerial vehicle (UAV) system is established; the impedance position planner includes a nonlinear disturbance observer and an impedance controller. The position controller is used to receive the error between the actual position and the desired position of the tethered UAV, and convert the position error into a three-axis desired acceleration signal according to a preset control law. The control quantity solver is used to calculate the required total lift, desired attitude angle and corresponding cable tension of the tethered UAV based on the desired acceleration, and inputs the required total lift, desired attitude angle and cable tension together with the external given quantity to the attitude controller; The attitude controller is used to generate a corresponding rotational torque control quantity based on the error between the actual attitude angle and the desired attitude angle of the tethered UAV and according to the corresponding control law.

[0014] Secondly, the present invention provides a control system for a tethered unmanned aerial vehicle (UAV) with strong wind resistance, the control system comprising: The acquisition module is used to acquire the original expected trajectory data, real-time status data, and the set tethered drone wind-resistant area; the real-time status data includes position data, velocity data, attitude angle data, and angular velocity data; the tethered drone wind-resistant area is used to characterize the spatial range in which the tethered drone maintains safe flight under the combined action of tether tension and rotor thrust. The first determination module is used to control the tethered drone to enter an emergency control mode when it is determined from the position data that the tethered drone has moved into the cable-assisted wind-resistant area; the emergency control mode is used to characterize the mode of activating the coordination solver to incorporate cable tension into the intermediate control quantity to achieve coordinated anti-disturbance control of rotor thrust and cable tension; The second determination module is used to control the tethered drone to enter the normal control mode when it is determined from the position data that the tethered drone has moved outside the cable-assisted wind-resistant area; the normal control mode is used to characterize the mode in which the normal solver is activated to achieve the hovering control of the tethered drone by relying on rotor thrust and attitude adjustment. The determination module is used to determine the disturbance estimate based on the real-time state data and the nonlinear disturbance observer; The first control module is configured to, when the disturbance estimate exceeds the disturbance threshold, calculate the target desired trajectory data based on the disturbance estimate, the original desired trajectory data, and the impedance controller, and generate control commands based on the target desired trajectory data to control the tethered UAV.

[0015] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and used to run on the processor, wherein the processor executes the computer program to implement the tethered unmanned aerial vehicle strong wind resistance control method described in the first aspect.

[0016] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the tethered unmanned aerial vehicle (UAV) strong wind resistance control method described in the first aspect.

[0017] The significant advantages of this invention are as follows: when the location data indicates that the tethered UAV has moved into the tether-assisted wind-resistant area, the control enters an emergency control mode; when the location data indicates that the tethered UAV has moved outside the tether-assisted wind-resistant area, the control enters a normal control mode; based on real-time status data and the disturbance estimate determined by the nonlinear disturbance observer exceeding the disturbance threshold, control commands are generated and executed based on the disturbance estimate, the original desired trajectory data, and the target desired trajectory data calculated by the impedance controller. In the normal control mode of this invention, if the disturbance is small, the UAV autonomously adjusts its attitude and thrust to achieve disturbance-resistant hovering; if the disturbance exceeds the threshold, the UAV is guided into the tether-assisted wind-resistant area; in the emergency control mode, the tether tension is introduced as an intermediate control variable to achieve coordinated disturbance resistance by the tether and rotor, significantly improving the stable hovering capability and operational reliability in complex wind fields. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the wind disturbance affecting a tethered drone.

[0019] Figure 2 This is the first flowchart of the strong wind resistance control method for tethered unmanned aerial vehicles according to Embodiment 1 of the present invention.

[0020] Figure 3 This is the second flowchart of the strong wind resistance control method for tethered unmanned aerial vehicles according to Embodiment 1 of the present invention.

[0021] Figure 4 This is the third flowchart of the strong wind resistance control method for tethered unmanned aerial vehicles according to Embodiment 1 of the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the application of the tethered unmanned aerial vehicle (UAV) strong wind resistance control method of Embodiment 1 of the present invention.

[0023] Figure 6 This is a schematic diagram of the first module of the tethered unmanned aerial vehicle (UAV) strong wind resistance control system according to Embodiment 2 of the present invention.

[0024] Figure 7 This is a schematic diagram of the second module of the tethered unmanned aerial vehicle (UAV) strong wind resistance control system according to Embodiment 2 of the present invention.

[0025] Figure 8 This is a schematic diagram of the electronic device according to Embodiment 3 of the present invention. Detailed Implementation

[0026] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0027] Example 1: The control method for tethered drones with strong wind resistance in this embodiment is as follows: Figure 2 As shown, the control method includes: S11. Acquire the original expected trajectory data, real-time status data, and set tethered wind-resistant zone of the tethered drone; real-time status data includes position data, velocity data, attitude angle data, and angular velocity data; the tethered wind-resistant zone is used to characterize the spatial range in which the tethered drone maintains safe flight under the combined action of rotor thrust and tether tension. S121. When the location data determines that the tethered drone has moved into the cable-assisted wind-resistant area, the tethered drone is controlled to enter the emergency control mode. The emergency control mode is used to characterize the mode of activating the coordination solver to incorporate the cable tension into the intermediate control quantity to achieve coordinated anti-disturbance control of rotor thrust and cable tension. S122. When the location data determines that the tethered drone has moved outside the tethered wind-resistant area, the tethered drone is controlled to enter the normal control mode. The normal control mode is used to characterize the mode in which the normal solver is activated to achieve hovering control by relying on rotor thrust and attitude adjustment. S13. Determine the disturbance estimate based on real-time state data and a nonlinear disturbance observer; S141. When the disturbance estimate exceeds the disturbance threshold, calculate the target expected trajectory data based on the disturbance estimate, the original expected trajectory data, and the impedance controller, and generate control commands to control the tethered UAV based on the target expected trajectory data. S142. If the disturbance estimate does not exceed the disturbance threshold, generate control commands based on the original expected trajectory data to control the tethered UAV.

[0028] In this embodiment, as Figure 1 As shown, a tethered drone is a type of drone that is connected to a ground platform via a flexible cable and can hover for extended periods or fly at low speeds. Real-time status data can include the tethered drone's three-axis position, three-axis velocity, attitude angles, and angular velocity in an inertial coordinate system.

[0029] By determining whether the tethered drone has moved into or outside the tethered wind-resistant area based on location data, the normal control mode or emergency control mode is determined. In the emergency control mode, the cable tension is introduced as an intermediate control quantity to achieve coordinated interference resistance between the cable and the rotor.

[0030] In conventional control mode, when the disturbance estimate exceeds the disturbance threshold, it indicates that the disturbance rejection capability has reached its limit, requiring the use of cable tension for coordinated disturbance rejection control. The target desired trajectory data is input as an outer-loop position command to the inner-loop position-attitude controller. The inner-loop controller generates the corresponding desired attitude angle and control commands based on the position error, thereby driving the tethered UAV to complete coordinated attitude and position adjustments. This achieves a compliant position adjustment mechanism based on disturbance perception, enabling the tethered UAV to balance tracking performance and disturbance rejection capability under complex wind conditions, significantly improving the overall stability and safety of the system. When the disturbance estimate does not exceed the disturbance threshold, it indicates that the tethered UAV can achieve disturbance-resistant hovering control based on the robustness of its own control system, without needing to adjust the original desired trajectory data. That is, if the disturbance does not exceed the disturbance threshold, the tethered UAV autonomously adjusts its attitude and thrust to achieve disturbance-resistant hovering; if the disturbance exceeds the disturbance threshold, the tethered UAV is guided into the cable-assisted wind-resistant zone. The mode switching control framework under this method can effectively avoid the additional risks brought about by performing drone recovery operations under strong disturbance environments, and effectively utilize the cable pulling auxiliary anti-disturbance effect in emergency mode, thereby achieving stable and continuous operation of tethered drones under all-weather and multi-scenario conditions.

[0031] In one embodiment, such as Figure 3 As shown, step S141 includes: S1411. Calculate the position adjustment amount based on the disturbance estimate and the impedance controller; S1412. Calculate the target expected trajectory data based on the original expected trajectory data and the position adjustment amount.

[0032] Among them, the impedance controller obtains the position adjustment amount based on the disturbance estimate and calculation using a set mass damping stiffness dynamic model; The mathematical expression for the mass-damped stiffness dynamic model is: ; This represents the virtual mass matrix, used to characterize the system's inertial response to disturbances. This represents the virtual damping matrix, used to adjust the convergence speed of the system and suppress oscillations; This represents the virtual stiffness matrix, used to determine the mapping relationship between position offset and disturbance; Indicates the amount of position adjustment.

[0033] In this embodiment, after obtaining the disturbance estimate of the external disturbance, an impedance control concept is introduced. By constructing a mass damping stiffness dynamic model between the UAV and the external disturbance, the desired position of the UAV is adaptively adjusted, thereby guiding it to move within the cable tension-assisted wind-resistant domain and enabling the UAV to respond compliantly to changes in external disturbances. Compared to traditional rigid position tracking methods, this method introduces equivalent dynamic characteristics, allowing the system to ensure stability while also considering disturbance rejection performance and response smoothness. By rationally designing the above parameter matrix, the tethered UAV can exhibit the desired dynamic response characteristics under different disturbance intensities.

[0034] The mathematical expression for the target desired trajectory data is set as follows: ; In the formula, This represents the original expected trajectory data. This represents the target's expected trajectory data after disturbance compensation. This method explicitly maps external disturbance information into position adjustment amounts, enabling the UAV to actively shift to a more stable hovering area when subjected to strong disturbances, i.e., the cable tension-assisted wind resistance zone.

[0035] In one embodiment, such as Figure 4 As shown, the control method also includes: S101. Establish a dynamic model of the tethered unmanned aerial vehicle system; the dynamic model includes an attitude dynamic model and a tethered cable dynamic model. S102. Determine the rope-assisted wind-resistant area based on the posture dynamics model and the mooring rope dynamics model; Among them, the pose dynamics model is used to determine the relationship between the three-axis position, velocity and attitude angle in the inertial coordinate system; the tethered cable dynamics model is used to discretize the cable into multiple micro-elements, and determine the motion relationship of each micro-element based on the mass of each micro-element, air resistance and tension of adjacent micro-elements. The mathematical expression for the rope-assisted wind-resistant zone is: ; This indicates the horizontal distance between the tethered ground platform and the tethered drone; Indicates the altitude of the tethered drone relative to the tethered ground platform; This indicates the maximum length of the rope or cable.

[0036] In this embodiment, the mathematical expression of the pose dynamics model is as follows: ; in, These represent the three-axis positions and velocities of the UAV in the ground inertial coordinate system, respectively. For drone quality; This represents the magnitude of gravitational acceleration. ; This represents the rotation matrix of the tethered unmanned aerial vehicle (UAV) system to the ground inertial coordinate system, expressed as the roll angle. Pitch angle and yaw angle Characterization; This indicates the total lift generated by the drone's rotors. This indicates the tension at the connection point between the tethering cable and the drone; This represents the unit vector indicating the direction of cable tension in the ground-based inertial coordinate system. This indicates the angular velocity of the drone's rotation; express The cross product matrix; This represents the moment of inertia of the drone. This indicates the rotational torque generated by the rotor.

[0037] The mathematical expression for the dynamic model of the tethered cable is as follows: ; in, Indicates the first The mass of a segment of cable micro-element; Indicates the first The second derivative of the position vector of the infinitesimal element of the cable segment; Represents the gravitational acceleration vector; Indicates the first The air resistance experienced by a small element of a rope segment; Indicates the first The tensile force on a small element of a rope segment; This indicates the number of segments into which the mooring rope is divided.

[0038] Within the tethered UAV's wind-resistant zone assisted by cable tension, the stress state changes from a balance solely dependent on rotor thrust to a synergistic balance involving both rotor thrust and cable tension—essentially switching from conventional control to emergency control. Cable tension no longer exists merely as a constraint but as an effective disturbance rejection component participating in the system's force balance. Its direction, along the cable towards the ground anchor point, can to some extent share the horizontal loads caused by external wind disturbances, thereby reducing the tethered UAV's dependence on attitude adjustment and thrust output.

[0039] The contribution of cable tension to wind resistance exhibits a clear regional dependence; that is, the tension component can only effectively counteract wind disturbances when the UAV is within a specific spatial range. If the location deviates from this range, the tension may instead exacerbate the system burden or reduce the control margin. Therefore, it is necessary to analyze the force balance relationship of the UAV under wind disturbance based on the dynamic equations, clarify the coupling mechanism between rotor thrust, cable tension, and external disturbances, and further characterize the contribution of tension to wind resistance at different spatial locations. Based on the above analysis, by decomposing and reconstructing the system force balance equations, the feasibility conditions for cable tension to participate in wind resistance can be established, and the mathematical expression of the cable tension-assisted wind resistance region can be derived. Under equilibrium conditions, the tethered drone and each bead point are in a state of force equilibrium. Given the drone's lift, tilt angle, and cable tension angle, the calculated cable tension is: ; By examining the first By establishing the force equilibrium equations for each bead point, we can obtain: ; in, Indicates the first The magnitude of the tension on a rigid straight bar Indicates the first The inclination angle of the rigid straight rod. By recursively calculating, the limit position at which the tethered drone can resist the maximum wind disturbance under different cable lengths is obtained. Interpolating the limit position yields the cable-assisted wind-resistant zone of the tethered drone.

[0040] In one embodiment, such as Figure 4 As shown, the control method also includes: S103. Establish an anti-disturbance hovering controller for a tethered unmanned aerial vehicle (UAV) system; the anti-disturbance hovering controller includes a position controller, a control variable solver, and an attitude controller; the control variable solver includes a conventional solver and a coordinated solver. S104. Establish an impedance position planner for the tethered unmanned aerial vehicle system; the impedance position planner includes a nonlinear disturbance observer and an impedance controller. The position controller is used to receive the error between the actual position and the desired position of the tethered UAV, and convert the position error into a three-axis desired acceleration signal according to a preset control law. The control variable solver is used to calculate the required total lift, desired attitude angle and corresponding cable tension of the tethered UAV based on the desired acceleration, and inputs the required total lift, desired attitude angle and cable tension together with the external setpoint to the attitude controller. The attitude controller is used to generate the corresponding rotational torque control quantity based on the error between the actual attitude angle and the desired attitude angle of the tethered UAV and the corresponding control law.

[0041] In this embodiment, the cable tension, the required total lift, and the rotational torque control quantity are input into the dynamic model to form a closed-loop control system, thereby achieving disturbance-resistant hovering control of the UAV. It is important to emphasize that both the position controller and the attitude controller can be implemented using any one or a combination of proportional-integral-derivative control, sliding mode control, or model predictive control.

[0042] Secondly, the purpose of designing an impedance position planner is to introduce a mechanism into the control system capable of online sensing and estimation of unknown disturbances. This mechanism compliantly adjusts the desired position, enabling the tethered UAV to move into the cable tension-assisted wind-resistant zone under strong disturbances, thereby improving its disturbance rejection performance while ensuring system stability. An impedance position planner is constructed based on a disturbance sensing outer loop using a nonlinear disturbance observer and incorporating impedance control principles. The estimated disturbance information is mapped to an adaptive correction value for the desired position, achieving compliant position adjustment and steady-state error suppression for the tethered UAV in windy environments.

[0043] Given that external disturbances during actual flight typically exhibit a certain degree of continuity and gradual variation, the following assumptions can be made: Disturbance term The rate of change is bounded over a short time, i.e., it satisfies the slow time-varying condition. Based on this, the mathematical expression of the designed nonlinear perturbation observer is as follows: ; in, These are intermediate state variables of the observer; This is an estimate of the external disturbance; The gain matrix is ​​a symmetric positive definite matrix, and its size directly affects the convergence speed and estimation accuracy of the observer. By appropriately selecting the gain matrix... It can achieve rapid and accurate estimation of external disturbances while ensuring system stability.

[0044] In one embodiment, the mathematical expression for the coordinated solver is: ; in, This indicates the cable tension required to tether the drone. express The three-axis components; This indicates the three-axis output of the position loop controller; This represents the desired roll angle, desired pitch angle, and desired yaw angle. Given from the outside; This represents the total lift per unit mass. Indicates the azimuth angle of the cable tension; It represents the acceleration due to gravity.

[0045] In this embodiment, when the tethered drone is within the tethered wind-resistant zone, the control variable solver switches to a coordinated solver. The coordinated control adjusts the intermediate control variables, incorporating the tethered cable tension required for wind resistance. The desired yaw and pitch angles are given externally at the same time. The above mathematical expression is obtained after reconstructing and solving the coordinated solver.

[0046] In one embodiment, such as Figure 5 As shown, a mode-switching-based disturbance rejection controller is configured to determine whether to activate the conventional solver or the coordinated solver based on real-time state data. A disturbance-aware impedance-based position planner is configured to output disturbance estimates from a nonlinear disturbance observer, input these estimates to the impedance controller to output position adjustments, and then implement position control based on these adjustments. This approach, based on the mode-switching disturbance rejection controller and the disturbance-aware impedance-based position planner, significantly improves stable hovering capabilities in complex wind fields, ensuring the operational reliability of tethered UAVs.

[0047] This embodiment provides a control method for tethered drones to withstand strong winds. By determining the position data, the method determines whether the tethered drone moves into or outside the tethered wind-resistant area, thus establishing two operating modes. In the normal control mode, if the disturbance is small, the drone autonomously adjusts its attitude and thrust to achieve disturbance-resistant hovering; if the disturbance exceeds the threshold, the drone is guided into the tethered wind-resistant area. In the emergency control mode, the cable tension is introduced as an intermediate control quantity to achieve coordinated disturbance resistance between the cable and the rotor, significantly improving the stable hovering capability and operational reliability in complex wind fields.

[0048] Example 2: The tethered drone's strong wind-resistant control system in this embodiment, such as Figure 6 As shown, the control system includes: The acquisition module 310 is used to acquire the original expected trajectory data, real-time status data and the set tethered drone wind-resistant area; the real-time status data includes position data, velocity data, attitude angle data and angular velocity data; the tethered drone wind-resistant area is used to characterize the spatial range in which the tethered drone maintains safe flight under the combined action of tether tension and rotor thrust. The first determination module 321 is used to control the tethered drone to enter the emergency control mode when the tethered drone moves into the cable-assisted wind-resistant area based on the position data; the emergency control mode is used to characterize the mode of activating the coordination solver to incorporate the cable tension into the intermediate control quantity to achieve the coordinated anti-disturbance control of rotor thrust and cable tension. The second determination module 322 is used to control the tethered drone to enter the normal control mode when the tethered drone moves outside the cable-assisted wind-resistant area based on the position data; the normal control mode is used to characterize the mode in which the normal solver is activated to achieve hovering control of the tethered drone by relying on rotor thrust and attitude adjustment. The determination module 330 is used to determine the disturbance estimate based on real-time state data and a nonlinear disturbance observer; The first control module 341 is used to calculate the target desired trajectory data based on the disturbance estimate, the original desired trajectory data and the impedance controller when the disturbance estimate exceeds the disturbance threshold, so as to generate control commands to control the tethered UAV based on the target desired trajectory data.

[0049] The second control module 342 is used to generate control commands to control the tethered drone based on the original expected trajectory data when the disturbance estimate does not exceed the disturbance threshold.

[0050] In this embodiment, the tethered drone is a drone connected to a ground platform via a flexible cable, capable of hovering for extended periods or flying at low speeds. Real-time status data may include the tethered drone's three-axis position, three-axis velocity, attitude angles, and angular velocity in an inertial coordinate system.

[0051] The first determination module 321 and the second determination module 322 determine whether the tethered UAV has moved into or outside the cable-assisted wind-resistant area based on the position data, and determine the normal control mode or the emergency control mode. In the emergency control mode, the cable tension is introduced as an intermediate control quantity to achieve coordinated anti-interference between the cable and the rotor.

[0052] In the normal control mode, when the disturbance estimate exceeds the disturbance threshold, it indicates that the anti-disturbance capability has reached its limit and the cable tension is needed to participate in the cooperative anti-disturbance control. The first control module 341 inputs the target desired trajectory data as an outer loop position command to the inner loop position-attitude controller. The inner loop controller generates the corresponding desired attitude angle and control command based on the position error, thereby driving the tethered UAV to complete the cooperative adjustment of attitude and position, realizing a compliant position adjustment mechanism based on disturbance perception. This allows the tethered UAV to balance tracking performance and anti-disturbance capability under complex wind disturbances, significantly improving the overall stability and safety of the system. When the disturbance estimate does not exceed the disturbance threshold, it indicates that the tethered UAV can achieve anti-disturbance hovering control based on the robustness of its own control system, and the second control module 342 does not need to adjust the original desired trajectory data. That is, if the disturbance does not exceed the disturbance threshold, the tethered UAV autonomously adjusts its attitude and thrust to achieve anti-disturbance hovering; if the disturbance exceeds the disturbance threshold, the tethered UAV is guided into the cable-assisted wind-resistant area. The mode switching control framework under this method can effectively avoid the additional risks brought about by performing drone recovery operations under strong disturbance environments, and effectively utilize the cable pulling auxiliary anti-disturbance effect in emergency mode, thereby achieving stable and continuous operation of tethered drones under all-weather and multi-scenario conditions.

[0053] In one embodiment, such as Figure 7 As shown, the first control module 341 includes: The first calculation unit 3411 is used to calculate the position adjustment amount based on the disturbance estimate and the impedance controller; The second calculation unit 3412 is used to calculate the target expected trajectory data based on the original expected trajectory data and the position adjustment amount.

[0054] Among them, the impedance controller obtains the position adjustment amount based on the disturbance estimate and calculation using a set mass damping stiffness dynamic model; The mathematical expression for the mass-damped stiffness dynamic model is: ; This represents the virtual mass matrix, used to characterize the system's inertial response to disturbances. This represents the virtual damping matrix, used to adjust the convergence speed of the system and suppress oscillations; This represents the virtual stiffness matrix, used to determine the mapping relationship between position offset and disturbance; Indicates the amount of position adjustment.

[0055] In this embodiment, after obtaining the disturbance estimate of the external disturbance, an impedance control concept is introduced. By constructing a mass damping stiffness dynamic model between the UAV and the external disturbance, the desired position of the UAV is adaptively adjusted, thereby guiding it to move within the cable tension-assisted wind-resistant domain and enabling the UAV to respond compliantly to changes in external disturbances. Compared to traditional rigid position tracking methods, this method introduces equivalent dynamic characteristics, allowing the system to ensure stability while also considering disturbance rejection performance and response smoothness. By rationally designing the above parameter matrix, the tethered UAV can exhibit the desired dynamic response characteristics under different disturbance intensities.

[0056] The mathematical expression for the target desired trajectory data is set as follows: ; In the formula, This represents the original expected trajectory data. This represents the target's expected trajectory data after disturbance compensation. This method explicitly maps external disturbance information into position adjustment amounts, enabling the UAV to actively shift to a more stable hovering area when subjected to strong disturbances, i.e., the cable tension-assisted wind resistance zone.

[0057] In one embodiment, such as Figure 7 As shown, the control system includes: The first module 301 is used to establish the dynamic model of the tethered unmanned aerial vehicle system; the dynamic model includes the pose dynamic model and the tethered cable dynamic model. The second module 302 is used to determine the rope-assisted wind-resistant area based on the pose dynamics model and the mooring rope dynamics model. Among them, the pose dynamics model is used to determine the relationship between the three-axis position, velocity and attitude angle in the inertial coordinate system; the tethered cable dynamics model is used to discretize the cable into multiple micro-elements, and determine the motion relationship of each micro-element based on the mass of each micro-element, air resistance and tension of adjacent micro-elements.

[0058] The mathematical expression for the rope-assisted wind-resistant zone is: ; This indicates the horizontal distance between the tethered ground platform and the tethered drone; Indicates the altitude of the tethered drone relative to the tethered ground platform; This indicates the maximum length of the rope or cable.

[0059] In this embodiment, the mathematical expression of the pose dynamics model is as follows: ; in, These represent the three-axis positions and velocities of the UAV in the ground inertial coordinate system, respectively. For drone quality; This represents the magnitude of gravitational acceleration. ; This represents the rotation matrix of the tethered unmanned aerial vehicle (UAV) system to the ground inertial coordinate system, expressed as the roll angle. Pitch angle and yaw angle Characterization; This indicates the total lift generated by the drone's rotors. This indicates the tension at the connection point between the tethering cable and the drone; This represents the unit vector indicating the direction of cable tension in the ground-based inertial coordinate system. This indicates the angular velocity of the drone's rotation; express The cross product matrix; This represents the moment of inertia of the drone. This indicates the rotational torque generated by the rotor.

[0060] The mathematical expression for the dynamic model of the tethered cable is as follows: ; in, Indicates the first The mass of a segment of cable micro-element; Indicates the first The second derivative of the position vector of the infinitesimal element of the cable segment; Represents the gravitational acceleration vector; Indicates the first The air resistance experienced by a small element of a rope segment; Indicates the first The tensile force on a small element of a rope segment; This indicates the number of segments into which the mooring rope is divided.

[0061] Within the tethered UAV's wind-resistant zone assisted by cable tension, the stress state changes from a balance solely dependent on rotor thrust to a synergistic balance involving both rotor thrust and cable tension—essentially switching from conventional control to emergency control. Cable tension no longer exists merely as a constraint but as an effective disturbance rejection component participating in the system's force balance. Its direction, along the cable towards the ground anchor point, can to some extent share the horizontal loads caused by external wind disturbances, thereby reducing the tethered UAV's dependence on attitude adjustment and thrust output.

[0062] The contribution of cable tension to wind resistance exhibits a clear regional dependence; that is, the tension component can only effectively counteract wind disturbances when the UAV is within a specific spatial range. If the location deviates from this range, the tension may instead exacerbate the system burden or reduce the control margin. Therefore, it is necessary to analyze the force balance relationship of the UAV under wind disturbance based on the dynamic equations, clarify the coupling mechanism between rotor thrust, cable tension, and external disturbances, and further characterize the contribution of tension to wind resistance at different spatial locations. Based on the above analysis, by decomposing and reconstructing the system force balance equations, the feasibility conditions for cable tension to participate in wind resistance can be established, and the mathematical expression of the cable tension-assisted wind resistance region can be derived. Under equilibrium conditions, the tethered drone and each bead point are in a state of force equilibrium. Given the drone's lift, tilt angle, and cable tension angle, the calculated cable tension is: ; By examining the first By establishing the force equilibrium equations for each bead point, we can obtain: ; in, Indicates the first The magnitude of the tension on a rigid straight bar Indicates the first The inclination angle of the rigid straight rod. By recursively calculating, the limit position at which the tethered drone can resist the maximum wind disturbance under different cable lengths is obtained. Interpolating the limit position yields the cable-assisted wind-resistant zone of the tethered drone.

[0063] In one embodiment, such as Figure 7 As shown, the control system includes: The third module 303 is used to establish an anti-interference hovering controller for the tethered unmanned aerial vehicle system. The anti-interference hovering controller includes a position controller, a control variable solver, and an attitude controller. The control variable solver includes a conventional solver and a coordinated solver. The fourth module 304 is used to establish the impedance position planner for the tethered unmanned aerial vehicle system; the impedance position planner includes a nonlinear disturbance observer and an impedance controller; The position controller is used to receive the error between the actual position and the desired position of the tethered UAV, and convert the position error into a three-axis desired acceleration signal according to a preset control law. The control variable solver is used to calculate the required total lift, desired attitude angle and corresponding cable tension of the tethered UAV based on the desired acceleration, and inputs the required total lift, desired attitude angle and cable tension together with the external setpoint to the attitude controller. The attitude controller is used to generate the corresponding rotational torque control quantity based on the error between the actual attitude angle and the desired attitude angle of the tethered UAV and the corresponding control law.

[0064] In this embodiment, the third module 303 inputs the cable tension, the required total lift, and the rotational torque control quantity into the dynamic model to form a closed-loop control system, thereby achieving disturbance-resistant hovering control of the UAV. It should be emphasized that both the position controller and the attitude controller can be implemented using any one or a combination of proportional-integral-derivative control, sliding mode control, or model predictive control.

[0065] Secondly, the fourth module 304 designs an impedance position planner. Its purpose is to introduce a mechanism into the control system capable of online sensing and estimation of unknown disturbances. By compliantly adjusting the desired position, the tethered UAV can move to the cable tension-assisted wind-resistant zone under strong disturbances, thereby improving its disturbance rejection performance while ensuring system stability. A disturbance sensing outer loop based on a nonlinear disturbance observer is designed, and an impedance position planner is constructed by combining impedance control principles. The estimated disturbance information is mapped to an adaptive correction amount for the desired position, enabling compliant position adjustment and steady-state error suppression of the tethered UAV in windy environments.

[0066] Given that external disturbances during actual flight typically exhibit a certain degree of continuity and gradual variation, the following assumptions can be made: Disturbance term The rate of change is bounded over a short time, i.e., it satisfies the slow time-varying condition. Based on this, the mathematical expression of the designed nonlinear perturbation observer is as follows: ; in, These are intermediate state variables of the observer; This is an estimate of the external disturbance; The gain matrix is ​​a symmetric positive definite matrix, and its size directly affects the convergence speed and estimation accuracy of the observer. By appropriately selecting the gain matrix... It can achieve rapid and accurate estimation of external disturbances while ensuring system stability.

[0067] In one embodiment, the mathematical expression for the coordinated solver is: ; in, This indicates the cable tension required to tether the drone. express The three-axis components; This indicates the three-axis output of the position loop controller; This represents the desired roll angle, desired pitch angle, and desired yaw angle. Given from the outside; This represents the total lift per unit mass. Indicates the azimuth angle of the cable tension; It represents the acceleration due to gravity.

[0068] In this embodiment, when the tethered drone is within the tethered wind-resistant zone, the control variable solver switches to a coordinated solver. The coordinated control adjusts the intermediate control variables, incorporating the tethered cable tension required for wind resistance. The desired yaw and pitch angles are given externally at the same time. The above mathematical expression is obtained after reconstructing and solving the coordinated solver.

[0069] This embodiment provides a control method for tethered drones to withstand strong winds. By determining the position data, the method determines whether the tethered drone moves into or outside the tethered wind-resistant area, thus establishing two operating modes. In the normal control mode, if the disturbance is small, the drone autonomously adjusts its attitude and thrust to achieve disturbance-resistant hovering; if the disturbance exceeds the threshold, the drone is guided into the tethered wind-resistant area. In the emergency control mode, the cable tension is introduced as an intermediate control quantity to achieve coordinated disturbance resistance between the cable and the rotor, significantly improving the stable hovering capability and operational reliability in complex wind fields.

[0070] Example 3: Figure 8 This is a schematic diagram of the structure of an electronic device provided in this embodiment. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the strong wind resistance control method for the tethered drone of Embodiment 1. Figure 8 The electronic device 80 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0071] like Figure 8 As shown, the electronic device 80 can be manifested as a general-purpose computing device, such as a server device. The components of the electronic device 80 may include, but are not limited to: at least one processor 81, at least one memory 82, and a bus 83 connecting different system components (including memory 82 and processor 81).

[0072] Bus 83 includes a data bus, an address bus, and a control bus.

[0073] The memory 82 may include volatile memory, such as random access memory (RAM) 821 and / or cache memory 822, and may further include read-only memory (ROM) 823.

[0074] The memory 82 may also include a program / utility 825 having a set (at least one) of program modules 824, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0075] The processor 81 executes various functional applications and data processing by running computer programs stored in the memory 82, such as the tethered drone strong wind resistance control method of Embodiment 1 of the present invention.

[0076] Electronic device 80 can also communicate with one or more external devices 84 (e.g., keyboard, pointing device, etc.). This communication can be performed via input / output (I / O) interface 85. Furthermore, the model-generated electronic device 80 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 86. Figure 8 As shown, network adapter 86 communicates with other modules of the model-generated electronic device 80 via bus 83. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the model-generated electronic device 80, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems.

[0077] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0078] Example 4: This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the tethered drone strong wind resistance control method of Embodiment 1.

[0079] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0080] In a possible implementation, the present invention can also be implemented as a program product comprising program code, which, when the program product is run on a terminal device, causes the terminal device to execute the steps of the tethered unmanned aerial vehicle strong wind resistance control method of Embodiment 1.

[0081] The program code for executing the present invention can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0082] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A control method for a tethered unmanned aerial vehicle (UAV) with strong wind resistance, characterized in that, The control method includes: Acquire the original desired trajectory data, real-time status data, and defined tethered wind-resistant zone of the tethered drone; the real-time status data includes position data, velocity data, attitude angle data, and angular velocity data; the tethered wind-resistant zone characterizes the spatial range within which the tethered drone maintains safe flight under the combined action of rotor thrust and tether tension; the mathematical expression for the tethered wind-resistant zone is: ； This indicates the horizontal distance between the tethered ground platform and the tethered drone; This indicates the height of the tethered drone relative to the tethered ground platform; Indicates the maximum length of the rope / cable; When the location data determines that the tethered drone has moved into the cable-assisted wind-resistant area, the tethered drone is controlled to enter the emergency control mode; the emergency control mode is used to characterize the mode of activating the coordination solver to incorporate cable tension into the intermediate control quantity to achieve coordinated anti-disturbance control of rotor thrust and cable tension; When the location data determines that the tethered drone has moved outside the cable-assisted wind-resistant area, the tethered drone is controlled to enter the normal control mode; the normal control mode is used to characterize the mode in which the normal solver is activated to achieve hovering control by relying on rotor thrust and attitude adjustment; The disturbance estimate is determined based on the real-time state data and the nonlinear disturbance observer. If the disturbance estimate exceeds the disturbance threshold, target desired trajectory data is calculated based on the disturbance estimate, the original desired trajectory data, and the impedance controller, so as to generate control commands to control the tethered UAV based on the target desired trajectory data.

2. The control method for tethered unmanned aerial vehicles with strong wind resistance as described in claim 1, characterized in that, The step of calculating the target desired trajectory data based on the disturbance estimate, the original desired trajectory data, and the impedance controller includes: The position adjustment amount is calculated based on the disturbance estimate and the impedance controller; The target expected trajectory data is calculated based on the original expected trajectory data and the position adjustment amount.

3. The tethered unmanned aerial vehicle (UAV) strong wind resistance control method as described in claim 2, characterized in that, The impedance controller calculates the position adjustment amount based on the disturbance estimate using a set mass damping stiffness dynamic model. The mathematical expression for the mass-damped stiffness dynamics model is: ； in, This represents the virtual mass matrix, used to characterize the system's inertial response to disturbances. This represents the virtual damping matrix, used to adjust the convergence speed of the system and suppress oscillations; This represents the virtual stiffness matrix, used to determine the mapping relationship between position offset and disturbance; Indicates the amount of position adjustment.

4. The control method for tethered unmanned aerial vehicles with strong wind resistance as described in claim 1, characterized in that, The mathematical expression for the coordinated solver is: ； in, This indicates the cable tension required to tether the drone. express The three-axis components; This indicates the three-axis output of the position loop controller; This represents the desired roll angle, desired pitch angle, and desired yaw angle. Given from the outside; This represents the total lift per unit mass. Indicates the azimuth angle of the cable tension; It represents the acceleration due to gravity.

5. The control method for tethered unmanned aerial vehicles with strong wind resistance as described in claim 1, characterized in that, The control method includes: If the disturbance estimate does not exceed the disturbance threshold, control commands are generated based on the original expected trajectory data to control the tethered drone.

6. The control method for tethered unmanned aerial vehicles with strong wind resistance as described in claim 1, characterized in that, The control method further includes: A dynamic model of the tethered unmanned aerial vehicle system is established; the dynamic model includes an attitude dynamic model and a tethered cable dynamic model. The rope-assisted wind-resistant area is determined based on the posture dynamics model and the mooring rope dynamics model. The pose dynamics model is used to determine the relationship between the three-axis position, velocity and attitude angle in the inertial coordinate system. The tethered cable dynamic model is used to discretize the cable into multiple micro-elements, and to determine the motion relationship of each micro-element based on the mass of each micro-element, air resistance, and tension of adjacent micro-elements.

7. The tethered unmanned aerial vehicle (UAV) strong wind resistance control method as described in claim 6, characterized in that, The control method further includes: An anti-interference hovering controller for a tethered unmanned aerial vehicle (UAV) system is established; the anti-interference hovering controller includes a position controller, a control variable solver, and an attitude controller; the control variable solver includes a conventional solver and a coordinated solver. An impedance position planner for a tethered unmanned aerial vehicle (UAV) system is established; the impedance position planner includes a nonlinear disturbance observer and an impedance controller. The position controller is used to receive the error between the actual position and the desired position of the tethered UAV, and convert the position error into a three-axis desired acceleration signal according to a preset control law. The control quantity solver is used to calculate the required total lift, desired attitude angle and corresponding cable tension of the tethered UAV based on the desired acceleration, and inputs the required total lift, desired attitude angle and cable tension together with the external given quantity to the attitude controller; The attitude controller is used to generate a corresponding rotational torque control quantity based on the error between the actual attitude angle and the desired attitude angle of the tethered UAV and according to the corresponding control law.

8. A control system for a tethered unmanned aerial vehicle (UAV) with strong wind resistance, characterized in that, The control system includes: The acquisition module is used to acquire the original expected trajectory data, real-time status data, and a defined tethered wind-resistant zone of the tethered drone. The real-time status data includes position data, velocity data, attitude angle data, and angular velocity data. The tethered wind-resistant zone characterizes the spatial range within which the tethered drone maintains safe flight under the combined action of tether tension and rotor thrust. The mathematical expression for the tethered wind-resistant zone is: ； This indicates the horizontal distance between the tethered ground platform and the tethered drone; This indicates the height of the tethered drone relative to the tethered ground platform; Indicates the maximum length of the rope / cable; The first determination module is used to control the tethered drone to enter an emergency control mode when it is determined from the position data that the tethered drone has moved into the cable-assisted wind-resistant area; the emergency control mode is used to characterize the mode of activating the coordination solver to incorporate cable tension into the intermediate control quantity to achieve coordinated anti-disturbance control of rotor thrust and cable tension; The second determination module is used to control the tethered drone to enter the normal control mode when it is determined from the position data that the tethered drone has moved outside the cable-assisted wind-resistant area; the normal control mode is used to characterize the mode in which the normal solver is activated to achieve the hovering control of the tethered drone by relying on rotor thrust and attitude adjustment. The determination module is used to determine the disturbance estimate based on the real-time state data and the nonlinear disturbance observer; The first control module is configured to, when the disturbance estimate exceeds the disturbance threshold, calculate the target desired trajectory data based on the disturbance estimate, the original desired trajectory data, and the impedance controller, and generate control commands based on the target desired trajectory data to control the tethered UAV.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and for running on the processor, characterized in that, When the processor executes the computer program, it implements the tethered unmanned aerial vehicle (UAV) strong wind resistance control method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the tethered unmanned aerial vehicle (UAV) strong wind resistance control method according to any one of claims 1-7.

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