Control method and related device for tethered lift wing multi-rotor unmanned aerial vehicle based on interference adaptation

Abstract

The application discloses a tethered lift wing multi-rotor unmanned aerial vehicle control method based on interference self-adaption and related devices, and relates to the technical field of unmanned aerial vehicles, and the technical solution points are as follows: real-time estimation of external disturbance force and external disturbance moment according to the mass, speed and rotational angular velocity of the tethered lift wing multi-rotor; determination of the expected yaw angle of the tethered lift wing multi-rotor according to the yaw angle and external disturbance moment of the tethered lift wing multi-rotor; determination of the expected total rotor thrust and thrust direction of the tethered lift wing multi-rotor according to the actual hovering position, speed, expected hovering position and external disturbance force of the tethered lift wing multi-rotor, and transformation of the thrust direction into the expected attitude angle of the tethered lift wing multi-rotor; determination of the expected total controlled moment of the tethered lift wing multi-rotor according to the expected attitude angle and expected yaw angle of the tethered lift wing multi-rotor; and realization of the self-adaptive alignment of the wind direction of the tethered lift wing multi-rotor unmanned aerial vehicle in the hovering and flying process in response to the expected total rotor thrust and total controlled moment.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically, to a control method and related apparatus for a tethered lifting wing multirotor UAV based on interference adaptive control. Background Technology

[0002] Tethered lifting-wing multirotor UAVs face a prominent challenge in practical operations: yaw control and hovering stability in complex wind conditions. Tethered lifting-wing multirotor UAVs typically employ aerodynamic shapes such as swept wings, winglets, and vertical tails. These shapes provide good yaw stability during cruise flight, but during hovering or low-speed flight, when encountering horizontal crosswinds from directions other than the nose, the UAV will experience significant lateral aerodynamic forces and yaw disturbance moments.

[0003] Existing UAV flight control methods mainly fall into two categories regarding the handling of external disturbances. The first category is typical PID control, which is simple in structure and technically mature, but the controller parameters are fixed and difficult to adaptively adjust according to changes in the external environment, resulting in a significant decrease in control accuracy under strong wind disturbances. The second category is Active Disturbance Rejection Control (ADRC), such as attitude control based on Extended State Observer (ESO) and linear ADRC based on Linear Extended State Observer (LESO). These methods estimate the total disturbance of the system through the observer and compensate for it, thus improving the disturbance rejection performance. However, their design goal is still to suppress disturbances and maintain attitude angle stability, without changing the basic idea of ​​adversarial yaw control.

[0004] Therefore, existing control methods are insufficient to effectively address the decline in flight stability and control accuracy under adverse environments such as strong winds and complex terrain. Summary of the Invention

[0005] The purpose of this invention is to provide a control method and related device for a tethered lifting wing multi-rotor UAV based on interference adaptive control, which solves the problem that existing control methods are difficult to effectively cope with the decline in flight stability and control accuracy in harsh environments such as strong winds and complex terrain.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A first aspect of the present invention provides a control method for a tethered lifting wing multirotor unmanned aerial vehicle based on disturbance adaptation, comprising:

[0008] The external disturbance force and external disturbance torque are estimated in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor.

[0009] The desired yaw angle of the tethered lifting multirotor is determined based on the yaw angle of the tethered lifting multirotor and the external disturbance torque.

[0010] The desired total rotor thrust and thrust direction of the tethered lifting multi-rotor are determined based on the actual hovering position, speed, desired hovering position, and external disturbance force of the tethered lifting multi-rotor, and the thrust direction is transformed into the desired attitude angle of the tethered lifting multi-rotor.

[0011] The desired total controlled torque of the tethered lifting multirotor is determined based on the desired attitude angle and desired yaw angle of the tethered lifting multirotor.

[0012] In response to the desired total rotor thrust and total controlled torque, the tethered lifting wing multi-rotor UAV can adaptively align with the wind direction during hovering and flight.

[0013] A second aspect of the present invention provides a tethered lifting wing multirotor unmanned aerial vehicle control system based on interference adaptation, comprising:

[0014] The disturbance observation module is used to estimate the external disturbance force and external disturbance torque in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor.

[0015] The yaw control module is used to determine the desired yaw angle of the tethered lifting multirotor based on the yaw angle of the tethered lifting multirotor and the external disturbance torque.

[0016] The position control module is used to determine the desired total rotor thrust and thrust direction of the tethered lifting wing multi-rotor based on the actual hovering position, speed, desired hovering position and external disturbance force of the tethered lifting wing multi-rotor, and to transform the thrust direction into the desired attitude angle of the tethered lifting wing multi-rotor.

[0017] The attitude control module is used to determine the desired total controlled torque of the tethered lifting multi-rotor based on the desired attitude angle and desired yaw angle of the tethered lifting multi-rotor.

[0018] The power control module is used to enable the tethered lifting wing multi-rotor UAV to adaptively align with the wind direction during hovering and flight, in response to the desired total rotor thrust and total controlled torque.

[0019] A third aspect of the present invention provides a tethered lifting wing multi-rotor unmanned aerial vehicle, including a memory and a processor;

[0020] A memory for storing computer programs, the computer programs including program instructions;

[0021] A processor is configured to execute the program instructions to cause the tethered lifting wing multirotor unmanned aerial vehicle to perform the steps of a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control method as provided in the first aspect of the present invention.

[0022] A fourth aspect of the present invention provides a computer-readable storage medium encoded with program instructions for causing one or more programmable processors to be configured to be configured as a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control system as provided in the second aspect of the present invention or to perform a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control method as provided in the first aspect of the present invention.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention performs disturbance observation and estimation on tethered lifting wing multirotors. By combining the mass, velocity, and rotational angular velocity of the tethered lifting wing multirotor, it estimates the external disturbance force and torque in real time, providing feedforward compensation signals for position and yaw control. Compared to the fixed-parameter PID control in existing technologies, this invention can sense and compensate for complex aerodynamic disturbances in real time, improving control accuracy and robustness under strong wind disturbances. Furthermore, it employs admittance control principles to construct adaptive alignment yaw control. By combining the yaw angle of the tethered lifting wing multirotor and the external disturbance torque, it determines the desired yaw angle of the tethered lifting wing multirotor, enabling the tethered lifting wing multirotor UAV to move in accordance with the external yaw disturbance torque. This fully utilizes the yaw self-stability provided by the swept wing, winglets, and vertical tail, allowing the UAV to... The human-machine interface automatically aligns with the wind direction like a weather vane; it feeds back external disturbances to the position control loop for compensation, and combines the actual hovering position, speed, and desired hovering position of the tethered lifting wing multi-rotor to obtain the desired total rotor thrust and thrust direction. The thrust direction is then transformed into the desired attitude angle of the tethered lifting wing multi-rotor to counteract disturbances caused by complex aerodynamic forces, achieving adaptive headwind hovering control of the tethered lifting wing multi-rotor UAV in adverse wind conditions. Finally, by combining the desired attitude angle and desired yaw angle of the tethered lifting wing multi-rotor, the desired total controlled torque of the tethered lifting wing multi-rotor is determined, controlling the rotor to generate the corresponding torque, thereby achieving attitude control. Ultimately, the nose direction of the lifting wing multi-rotor can adaptively and actively align with the wind direction. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a flowchart illustrating the interference-adaptive tethered lifting wing multirotor UAV control method provided in an embodiment of the present invention.

[0027] Figure 2 A schematic diagram of the transfer function for estimating external disturbance force and external disturbance torque provided for an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the transfer function for determining the desired yaw angle provided in an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of the principle of the tethered lifting wing multi-rotor UAV control system based on interference adaptation provided in an embodiment of the present invention;

[0030] Figure 5 The graphs showing the changes over time of level 7, 8, 9, and 10 horizontal crosswinds experienced by the tethered lifting multi-rotor provided in the embodiments of the present invention.

[0031] Figure 6 The simulation results of a tethered lifting multi-rotor hovering at a fixed point when encountering a horizontal crosswind at an altitude of 300m, provided in an embodiment of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0033] It should be noted that the terms "comprising" or "may include" used in the various embodiments of this application indicate the presence of the claimed function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms "comprising," "having," and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or the possibility of adding one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing.

[0034] Existing UAV flight control methods mainly fall into two categories regarding the handling of external disturbances. The first category is typical PID control, which is simple in structure and technically mature, but the controller parameters are fixed and difficult to adaptively adjust according to changes in the external environment, resulting in a significant decrease in control accuracy under strong wind disturbances. The second category is Active Disturbance Rejection Control (ADRC), such as attitude control based on Extended State Observer (ESO) and linear ADRC based on Linear Extended State Observer (LESO). These methods estimate the total disturbance of the system through the observer and compensate for it, thus improving the disturbance rejection performance. However, their design goal is still to suppress disturbances and maintain attitude angle stability, without changing the basic idea of ​​adversarial yaw control.

[0035] To address the problem of decreased flight stability and control accuracy in tethered multi-rotor UAVs under harsh environments such as strong winds and complex terrain, this invention provides a disturbance-adaptive control method for tethered multi-rotor UAVs. This method performs disturbance observation and estimation on the tethered multi-rotor, and estimates external disturbance forces and moments in real time by combining the mass, velocity, and rotational angular velocity of the tethered multi-rotor. This provides feedforward compensation signals for position control and yaw control. Compared to the fixed-parameter PID control in existing technologies, this invention can sense and compensate for complex aerodynamic disturbances in real time, improving control accuracy and robustness under strong wind disturbances. Furthermore, an adaptive aligning yaw control is constructed using admittance control principles. The desired yaw angle of the tethered multi-rotor is determined by combining the yaw angle of the tethered multi-rotor and the external disturbance moment, enabling the tethered multi-rotor UAV to move in accordance with the external yaw disturbance moment. This fully utilizes the yaw self-stability provided by the swept wing, winglets, and vertical tail, allowing the UAV to adapt to the yaw disturbance moment. The human-machine interface automatically aligns with the wind direction like a weather vane; it feeds back external disturbances to the position control loop for compensation, and combines the actual hovering position, speed, and desired hovering position of the tethered lifting wing multi-rotor to obtain the desired total rotor thrust and thrust direction. The thrust direction is then transformed into the desired attitude angle of the tethered lifting wing multi-rotor to counteract disturbances caused by complex aerodynamic forces, achieving adaptive headwind hovering control of the tethered lifting wing multi-rotor UAV in adverse wind conditions. Finally, by combining the desired attitude angle and desired yaw angle of the tethered lifting wing multi-rotor, the desired total controlled torque of the tethered lifting wing multi-rotor is determined, controlling the rotor to generate the corresponding torque, thereby achieving attitude control. Ultimately, the nose direction of the lifting wing multi-rotor can adaptively and actively align with the wind direction.

[0036] The kinematic model of a tethered lifting-wing multirotor UAV comprises two parts: position kinematics and attitude kinematics. Position kinematics describes the variation of the UAV's center of mass position in the geodetic coordinate system, while attitude kinematics describes the variation of the UAV's attitude angles (including pitch, roll, and yaw) over time. The tethered lifting-wing multirotor UAV achieves pitch and roll motion by generating differential torque through adjusting the rotational speeds of multiple rotors, and yaw motion through rotor anti-torque. Simultaneously, it utilizes the aerodynamic shape of swept wings, winglets, and the vertical tail to provide passive yaw self-stability. This kinematic model forms the basis for subsequent design of disturbance observation, yaw control, position control, and attitude control.

[0037] Figure 1 This is a flowchart illustrating a disturbance-adaptive tethered lifting wing multirotor UAV control method provided in an embodiment of the present invention. The method includes the following steps:

[0038] S101 estimates the external disturbance force and external disturbance torque in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor.

[0039] In this embodiment, the methods for measuring the mass, speed, and rotational angular velocity of the tethered lifting multi-rotor are common knowledge to those skilled in the art. For example, the speed can be measured using a GNSS system, and the rotational angular velocity can be measured using a gyroscope.

[0040] In some embodiments, the rotation matrix from the body coordinate system to the earth coordinate system and the rotor thrust of the tethered lifting multi-rotor are obtained; the external disturbance force is obtained by subtracting the product of the rotation matrix and the rotor thrust from the derivative of the velocity of the tethered lifting multi-rotor, and then adding the product of the mass of the UAV and the gravitational acceleration.

[0041] like Figure 2 As shown, based on the description in the above embodiments, the transfer function for determining the external disturbance force is:

[0042] ;in, The derivative of the velocity of a tethered lifting multi-rotor. Let m represent the rotation matrix from the body coordinate system to the ground coordinate system, m represent the mass of the UAV, and g represent the gravitational acceleration in the current flight area. This represents the actual rotor thrust of a tethered lifting multi-rotor.

[0043] In some embodiments, the rotor torque of the tethered lifting multi-rotor in the xyz direction is obtained; the rotor torque vector constructed from the rotor torque in the xyz direction is subtracted from the product of the derivative of the moment of inertia matrix and the rotational angular velocity, and the product of the cross product of the rotational angular velocity, the moment of inertia matrix, and the rotational angular velocity is added to obtain the resultant torque residual; the resultant torque residual is input into a low-pass filter to obtain the external disturbance torque.

[0044] like Figure 2 As shown, based on the description in the above embodiments, the transfer function for determining the external disturbance torque is:

[0045] ;ldf represents a low-pass filter, The derivative of the rotational angular velocity of a tethered lifting multirotor. Represents the moment of inertia matrix. This represents the rotor torque vector constructed from the rotor torques in the x, y, and z directions. , and These are the rotor moments in the x, y, and z directions, respectively. This indicates the rotational angular velocity of a tethered lifting multi-rotor.

[0046] S102, determine the desired yaw angle of the tethered lifting multi-rotor based on the yaw angle of the tethered lifting multi-rotor and the external disturbance torque.

[0047] In this embodiment, the lifting multirotor has a basic swept-wing structure and includes winglets, a vertical tail, etc., thus possessing a certain degree of yaw self-stability. When the external wind field is not blowing directly from the nose, the lifting multirotor will experience a yaw moment, and this yaw moment tends to align the nose with the wind direction. Admittance control, on the other hand, is a method of making the controlled object move in accordance with the action of external forces, rather than actively resisting the action of external forces. Therefore, this embodiment applies the concept of admittance control to the yaw control of the lifting multirotor, enabling the lifting multirotor to adapt to the yaw disturbance moment brought by the external environment, thereby automatically aligning with the wind direction. Through the estimation of the external disturbance force described in step S101 above, the magnitude of this yaw moment can be estimated relatively accurately. Therefore, this embodiment incorporates the external disturbance force into the admittance control, thereby achieving automatic alignment of the aircraft with the wind direction.

[0048] like Figure 3 As shown, the transfer function expression for determining the desired yaw angle of a tethered lifting multirotor is:

[0049] ;in, Represents the first adjustable positive real number. Represents the second adjustable positive real number. Indicates the yaw angle. Indicates the desired yaw angle. This represents the yaw moment caused by external disturbances, and is the third element of the external disturbance moment. The derivative representing the yaw angle. This represents the derivative of the desired yaw angle.

[0050] In this embodiment, the first and second adjustable positive real numbers for admittance control are set to 1 and 4, respectively.

[0051] S103, based on the actual hovering position, speed, desired hovering position and external disturbance force of the tethered lifting multi-rotor, determine the desired total rotor thrust and thrust direction of the tethered lifting multi-rotor, and transform the thrust direction into the desired attitude angle of the tethered lifting multi-rotor.

[0052] In this embodiment, the adaptive headwind hovering control system for a lifting multirotor integrates PID position control and DOB disturbance observation. PID control handles basic position adjustment, ensuring system stability and accuracy; while DOB disturbance observation estimates and compensates for disturbances caused by complex aerodynamic forces in real time, which are particularly significant under strong wind conditions. By directly feeding back the aerodynamic forces estimated by DOB disturbance observation to the PID control loop for compensation, adaptive headwind hovering control of the lifting multirotor under severe wind conditions can be achieved, significantly improving the system's robustness and operational efficiency. Based on the disturbance estimation described in the previous embodiment, this embodiment incorporates external disturbance force compensation into the position control, thereby achieving more precise position control.

[0053] Specifically, the first, second, and third control gain matrices of the position controller are obtained; the first control gain matrix is ​​multiplied by the difference between the desired hovering position and the actual hovering position of the tethered lifting wing multirotor to obtain a proportional term; the second control gain matrix is ​​multiplied by the integral of the difference between the desired hovering position and the actual hovering position of the tethered lifting wing multirotor to obtain an integral term; the third control gain matrix is ​​multiplied by the difference between the desired reference velocity and the velocity of the tethered lifting wing multirotor to obtain a differential term; the proportional, differential, and integral terms are added together, the external disturbance force is subtracted, and the product of mass and gravitational acceleration is added to obtain the desired acceleration of the tethered lifting wing multirotor UAV; the mass of the tethered lifting wing multirotor UAV is multiplied by the modulus of the desired acceleration to obtain the desired total rotor thrust of the tethered lifting wing multirotor; the desired thrust direction of the tethered lifting wing multirotor is determined based on the desired acceleration and the modulus of the desired acceleration.

[0054] The function expression for calculating the desired acceleration is as follows:

[0055] ;in, Indicates the speed of a tethered lifting multi-rotor. Indicates the actual hovering position. Indicates the desired hovering position. This represents the first control gain matrix. This represents the second control gain matrix. This represents the third control gain matrix. It indicates external disturbance forces.

[0056] It should be noted that the value of the first control gain matrix is ​​diag(1.5,1.5,3), the value of the second control gain matrix is ​​diag(0,0,0), and the value of the third control gain matrix is ​​diag(0.5,0.5,0.5).

[0057] Furthermore, the desired total rotor thrust and thrust direction can be calculated using the desired acceleration, specifically:

[0058] ,in, Indicates the expected acceleration. The magnitude of the desired acceleration is represented by the length of the spur. This represents the desired total rotor thrust.

[0059] It's important to understand that the output thrust direction needs to be transformed into the desired attitude angle of the tethered lifting multi-rotor before being transmitted to the attitude control system. The transformation process is as follows: Let the desired thrust direction be... The desired yaw angle is First, let the z-axis of the desired machine be... |;Then construct a horizontal reference vector from the desired yaw direction. and calculate , Thus, the desired rotation matrix is ​​obtained. According to the ZYX Euler angle convention, the desired rotation matrix is... Convert to desired roll angle and desired pitch angle The expected yaw angle is still taken as Therefore, the desired attitude angle is obtained. And input it into the attitude angle outer ring.

[0060] S104, determine the desired total controlled torque of the tethered lifting multi-rotor based on the desired attitude angle and desired yaw angle of the tethered lifting multi-rotor.

[0061] In this embodiment, for attitude control, based on the desired yaw angle and the desired attitude angle of the actual lifting multi-rotor, a cascaded PID controller can be designed to control the angle loop and the angular rate loop respectively, and finally control the torque generated by the lifting multi-rotor rotor, thereby achieving attitude control.

[0062] Attitude control employs a cascade feedback controller. The desired rotational angular velocity in the body coordinate system can be determined by the desired attitude angle. Specifically, the desired rotational angular velocity is determined based on the difference between the actual attitude angle and the desired attitude angle of the lifting multi-rotor and the angle feedback matrix. The functional relationship is as follows: ;in, It is an angle feedback matrix. Let be the angular difference between the actual attitude angle and the desired attitude angle of the lifting multi-rotor, where Indicates the roll angle. Indicates the pitch angle.

[0063] It should be noted that the value of the angle feedback matrix is ​​diag(5,5,5).

[0064] Furthermore, the desired rotational angular velocity is used as an input parameter and input into the function expression for the desired total controlled torque of the tethered lifting multi-rotor. The output is the desired total controlled torque of the tethered lifting multi-rotor, where the function expression is:

[0065] ;in, This represents the actual rotational angular velocity of the lifting multi-rotor at the current moment. With the desired rotational angular velocity The difference between them This represents the desired total controlled torque. This represents the upper limit of the expected total controlled torque. , and All of these are control parameters.

[0066] It should be noted that, , and The values ​​are diag(25,25,25), diag(3,3,5), and diag(0,0,0).

[0067] S105 enables tethered lifting wing multi-rotor UAVs to adaptively align with wind direction during hovering and flight, responding to the desired total rotor thrust and total controlled torque.

[0068] In this embodiment, the position control outputs the desired total rotor thrust. The attitude control output is the desired total controlled torque. The flight controller inputs these two desired control quantities into the control distributor and, based on the installation position, rotation direction, thrust coefficient, and anti-torque coefficient of each rotor, distributes the desired thrust and controlled torque to the desired rotational speeds of each rotor. Each desired rotational speed is limited and converted into electronic speed control (ESC) commands, which then drive the rotational speeds of each rotor, generating the actual total rotor thrust and actual total torque. The actual thrust and torque act on the UAV's translational and rotational dynamics, forming new position, velocity, attitude, and rotational angular velocity; these states, after sensor measurements and attitude calculations, are fed back to the disturbance observation, position control, and attitude control loops. Thus, Figure 3 Output and Ultimately, these commands are converted into control commands for each motor, and a closed-loop response is used to maintain the hovering position and adaptively align the yaw direction with the wind.

[0069] To verify the effectiveness of the interference-adaptive tethered lifting wing multirotor UAV control method proposed in this invention, a simulation platform was built using MATLAB R2022b under the Win10 operating system on a computer with a main frequency of 3.20 GHz and 32.00 GB of memory. The hovering control performance of the tethered lifting wing multirotor UAV in complex wind field environment was simulated and verified. The simulation environment settings are as follows:

[0070] (1) Simulation Platform and Model: A simulation system was constructed based on the kinematic model of a tethered lifting wing multi-rotor UAV. The kinematic model consists of two parts: position kinematics and attitude kinematics. Position kinematics describes the variation of the UAV's center of mass position in the geodetic coordinate system, while attitude kinematics describes the variation of the UAV's attitude angles (including pitch, roll, and yaw) over time. The tethered lifting wing multi-rotor UAV generates differential torque by adjusting the rotation speed of multiple rotors to achieve pitch and roll motions, and achieves yaw motion through rotor anti-torque. At the same time, it utilizes the aerodynamic shape of swept wings, winglets, and vertical tail to provide passive yaw self-stability.

[0071] (2) Control parameter settings: According to the design of the control method of the present invention, the parameters of disturbance observation, yaw control, position control and attitude control are set. Among them, the first adjustable positive real number of admittance control is 1, and the second adjustable positive real number is 4; the first control gain matrix of position control is diag(1.5,1.5,3), the second control gain matrix is ​​diag(0,0,0), and the third control gain matrix is ​​diag(0.5,0.5,0.5); the angle feedback matrix of attitude control is diag(5,5,5), and the three control parameters are diag(25,25,25), diag(3,3,5), and diag(0,0,0), respectively.

[0072] (3) Reference Figure 5 The graph shows the wind field variation curves over time for a tethered lifting wing multi-rotor UAV subjected to horizontal crosswinds of force 7, 8, 9, and 10. The horizontal axis represents time in seconds (s), ranging from 15s to 45s; the vertical axis represents wind speed in meters per second (m / s), ranging from 0m / s to 30m / s. The four curves correspond to force 7 wind (solid line), force 8 wind (dashed line), force 9 wind (dotted line), and force 10 wind (dotted line), respectively, all exhibiting an S-shaped step response characteristic: the wind speed remains relatively stable near 0m / s from 15s to 23s, increases sharply from 23s onwards, and gradually stabilizes between 30s and 33s. The steady-state wind speeds are approximately 17m / s for force 7, 21m / s for force 8, 24m / s for force 9, and 28m / s for force 10.

[0073] (4) Hovering task setting: The tethered lifting wing multi-rotor UAV is required to hover at a fixed point at an altitude of 300 meters, that is, the hovering position is expected to remain unchanged. When subjected to the above-mentioned horizontal crosswind interference, the control method of the present invention is used to achieve adaptive alignment with the wind direction and maintain fixed-point hovering.

[0074] Reference Figure 6 , Figure 6 The simulation results of a tethered lifting multi-rotor hovering at a height of 300m in a horizontal crosswind, provided in this embodiment of the invention, include six sub-graphs, each describing the UAV's position change and attitude angle response in three-dimensional space. The horizontal axis of all sub-graphs represents time, in seconds (s), ranging from 15s to 40s. Each sub-graph contains four curves, corresponding to wind levels 7 (solid line), 8 (dashed line), 9 (dotted line), and 10 (dotted line).

[0075] Figure 6 The top-left subplot shows the change in position in the x-direction over time, with the vertical axis representing the x-direction position in meters (m), ranging from -0.15m to 0.25m. Before 20 seconds, all curves remained relatively stable near 0. Around 22 seconds, a slight negative fluctuation appeared, reaching a low of approximately -0.12m. Around 28 seconds, a significant positive peak appeared, with the highest peak at level 10 winds, approaching 0.2m, before rapidly decaying back to 0. Higher wind levels resulted in greater disturbances, but all curves eventually converged to near 0, indicating that maintaining position in the x-direction provides good resistance to interference.

[0076] Figure 6 The left-center subplot shows the change in y-direction position over time, with the vertical axis representing the y-direction position in meters (m), ranging from 0m to 0.8m. This subplot illustrates the drift phenomenon under strong winds. The curves for winds of force 7, 8, and 9 show pulsed peaks around 28 seconds, approximately 0.32m, 0.43m, and 0.44m respectively, before rapidly converging back to near 0 (force 7 eventually returns to 0, while forces 8 and 9 show slight residual values). The curve for force 10 winds begins to drift continuously from 28 seconds, monotonically rising above 0.75m without converging, indicating that y-direction position control reaches saturation under this wind force. This result demonstrates that the control method of this invention can effectively suppress y-direction drift and achieve fixed-point hovering under wind conditions of force 7 to 9.

[0077] Figure 6The bottom left subplot shows the altitude change curve over time, with the vertical axis representing altitude in meters (m), ranging from -300.15m to -300m (negative altitude values ​​indicate downward relative to the reference point, due to the coordinate system definition). The reference altitude is approximately -300.05m. Three significant disturbances occur at 20s, 25s, and 28s, with a maximum subsidence of approximately 0.08m (to around -300.13m). All wind force curves almost completely overlap, indicating that altitude control (z-direction) has extremely strong robustness and is minimally affected by wind, verifying the excellent anti-interference performance of position control in the z-direction channel.

[0078] Figure 6 The top right subplot shows the roll angle over time, with the vertical axis representing the roll angle in radians (rad), ranging from -0.1 rad to 0.1 rad. It remains at 0 for the first 20 seconds; a negative trough appears around 23 seconds, at approximately -0.05 rad; a positive peak occurs between 27 and 29 seconds, at approximately +0.05 rad, followed by a decaying oscillation between 30 and 35 seconds, eventually stabilizing back to 0. The curves for each wind speed level highly overlap, indicating strong anti-interference capability of the roll channel and good robustness of the attitude controller in controlling the roll angle.

[0079] Figure 6 The right-center subplot shows the pitch angle versus time, with the vertical axis representing the pitch angle in radians (rad), ranging from -0.5 rad to 0.1 rad. It remains at 0 before 20 seconds; from 22 seconds onwards, it continuously decreases (increasing negatively), exhibiting a step response characteristic. The final steady-state value becomes more negative with increasing wind force: approximately -0.24 rad for force 7, approximately -0.30 rad for force 8, approximately -0.37 rad for force 9, and approximately -0.42 rad for force 10. This indicates that the UAV, in order to resist the oncoming wind, adopts a continuous pitch attitude, consistent with aerodynamic headwind trim characteristics, verifying the rationality of the position controller's thrust direction transformation to the desired attitude angle.

[0080] Figure 6The lower right subplot shows the yaw angle variation over time, with the vertical axis representing the yaw angle in radians (rad), ranging from -2.5 rad to 0.5 rad. It remains at 0 rad before 20 seconds; from 22 seconds onwards, it sharply deflects negatively, reaching a minimum of approximately -2.1 rad (approximately -120°) around 26 seconds; subsequently, it oscillates and stabilizes at approximately -1.5 rad (approximately -86°). The high consistency across all wind speed levels indicates that the yaw angle response primarily depends on the admittance control command and mooring constraints, rather than differences in wind force. This result verifies the effectiveness of the adaptive alignment yaw controller of this invention: when a horizontal crosswind blows from a direction other than the nose, the yaw controller, under the influence of the yaw disturbance torque estimated by the disturbance observer, uses admittance control to make the UAV move in accordance with the yaw disturbance torque, gradually turning the nose towards the wind direction, and finally stabilizing at a yaw angle aligned with the wind direction, thus achieving the core objective of adaptive alignment.

[0081] Based on the simulation results above, the tethered lifting wing multi-rotor UAV control method based on disturbance adaptation proposed in this invention has the following effects:

[0082] (1) Under the interference of level 7 to 10 horizontal crosswinds, the tethered lifting wing multi-rotor UAV can adaptively align with the wind direction through admittance control. The yaw angle eventually stabilizes at about -1.5 rad (about -86°), indicating that the nose direction has been aligned with the incoming wind direction, which verifies the effectiveness of the adaptive alignment yaw controller.

[0083] (2) Under wind conditions of level 7 to 9, the UAV can maintain a fixed hover in the x, y, and altitude directions, with position drift within an acceptable range and eventually convergence, verifying the anti-interference compensation effect of the position controller integrating PID and interference observer. Under level 10 wind conditions, the position in the y direction shows continuous drift, but the altitude and x directions remain stable, indicating that the method still has some control capability under extreme wind conditions.

[0084] (3) The roll angle and pitch angle can quickly converge to a steady state under the action of wind disturbance. The roll angle eventually stabilizes at around 0, and the pitch angle generates the corresponding windward trim attitude according to the wind force level, which verifies the effectiveness of the cascade PID attitude controller.

[0085] (4) The height control is extremely robust and is almost unaffected by wind. The maximum subsidence is only about 0.08m, indicating that the position controller has a significant interference compensation effect in the z-direction channel.

[0086] Figure 4 This is a schematic block diagram of a disturbance-adaptive tethered lifting wing multirotor UAV control system provided in an embodiment of the present invention. The system includes:

[0087] The disturbance observation module is used to estimate the external disturbance force and external disturbance torque in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor.

[0088] The yaw control module is used to determine the desired yaw angle of the tethered lifting multirotor based on the yaw angle of the tethered lifting multirotor and the external disturbance torque.

[0089] The position control module is used to determine the desired total rotor thrust and thrust direction of the tethered lifting wing multi-rotor based on the actual hovering position, speed, desired hovering position and external disturbance force of the tethered lifting wing multi-rotor, and to transform the thrust direction into the desired attitude angle of the tethered lifting wing multi-rotor.

[0090] The attitude control module is used to determine the desired total controlled torque of the tethered lifting multi-rotor based on the desired attitude angle and desired yaw angle of the tethered lifting multi-rotor.

[0091] The power control module is used to enable the tethered lifting wing multi-rotor UAV to adaptively align with the wind direction during hovering and flight, in response to the desired total rotor thrust and total controlled torque.

[0092] This invention also provides a tethered lifting-wing multirotor unmanned aerial vehicle (UAV). The tethered lifting-wing multirotor UAV includes a processor, a memory, a communication interface, and at least one communication bus for connecting the processor, memory, and communication interface. The memory includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (PROM), or portable read-only memory (CD-ROM), and is used for related instructions and data.

[0093] The communication interface is used to receive and send data. The processor can be one or more CPUs; if the processor is a single CPU, it can be a single-core CPU or a multi-core CPU. The processor in the electronic device reads one or more programs stored in memory and performs the following operations: estimates external disturbance forces and external disturbance torques in real time based on the mass, speed, and rotational angular velocity of the tethered lifting wing multirotor; determines the desired yaw angle of the tethered lifting wing multirotor based on its yaw angle and external disturbance torque; determines the desired total rotor thrust and thrust direction of the tethered lifting wing multirotor based on its actual hovering position, speed, desired hovering position, and external disturbance forces, and transforms the thrust direction into the desired attitude angle of the tethered lifting wing multirotor; determines the desired total controlled torque of the tethered lifting wing multirotor based on its desired attitude angle and desired yaw angle; and enables the tethered lifting wing multirotor UAV to adaptively align with the wind direction during hovering and flight in response to the desired total rotor thrust and total controlled torque.

[0094] It should be noted that the specific implementation of each operation can be described above. Figure 1 The corresponding description of the method embodiments shown indicates that the electronic device can be used to execute a tethered lifting wing multi-rotor UAV control method based on interference adaptation of the above method embodiments of this application, which will not be described in detail here.

[0095] This invention also provides a computer-readable storage medium, which is a memory device in a computer device for storing programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the operating system of the terminal. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the interference-adaptive tethered lifting wing multi-rotor UAV control method described in the above embodiments. Those skilled in the art should understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0096] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a tethered lifting wing multirotor unmanned aerial vehicle based on disturbance adaptive control, characterized in that, include: The external disturbance force and external disturbance torque are estimated in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor. The desired yaw angle of the tethered lifting multirotor is determined based on the yaw angle of the tethered lifting multirotor and the external disturbance torque. The desired total rotor thrust and thrust direction of the tethered lifting multi-rotor are determined based on the actual hovering position, speed, desired hovering position, and external disturbance force of the tethered lifting multi-rotor, and the thrust direction is transformed into the desired attitude angle of the tethered lifting multi-rotor. The desired total controlled torque of the tethered lifting multirotor is determined based on the desired attitude angle and desired yaw angle of the tethered lifting multirotor. In response to the desired total rotor thrust and total controlled torque, the tethered lifting wing multi-rotor UAV can adaptively align with the wind direction during hovering and flight.

2. The method according to claim 1, characterized in that, Determining external disturbance forces includes: Obtain the rotation matrix from the body coordinate system to the ground coordinate system and the actual rotor thrust of the tethered lifting multi-rotor; The external disturbance force is obtained by subtracting the product of the rotation matrix and the actual rotor thrust from the derivative of the velocity of the tethered lifting multi-rotor, and then adding the product of the mass of the UAV and the gravitational acceleration.

3. The method according to claim 1, characterized in that, Determining the external disturbance torque includes: Obtain the rotor torque of the tethered lifting multi-rotor in the xyz directions; The resultant torque residual is obtained by subtracting the rotor torque vector constructed from the rotor torques in the xyz directions from the product of the derivatives of the moment of inertia matrix and the rotational angular velocity, and then adding the cross product of the rotational angular velocity, the moment of inertia matrix, and the rotational angular velocity. The resultant torque residual is input into a low-pass filter to obtain the external disturbance torque.

4. The method according to claim 1, characterized in that, The functional expression for determining the desired yaw angle of a tethered lifting multirotor is: ;in, Represents the first adjustable positive real number. Represents the second adjustable positive real number. Indicates the yaw angle. Indicates the desired yaw angle. This represents the yaw moment caused by external disturbances, and is the third element of the external disturbance moment. The derivative representing the yaw angle. This represents the derivative of the desired yaw angle.

5. The method according to claim 1, characterized in that, Determine the desired total rotor thrust and thrust direction for the tethered lifting multi-rotor, including: Obtain the first control gain matrix, the second control gain matrix, and the third control gain matrix of the position controller; Multiply the first control gain matrix by the difference between the desired hovering position and the actual hovering position of the tethered lifting multirotor to obtain the proportional term; The integral term is obtained by multiplying the second control gain matrix by the integral of the difference between the desired hovering position and the actual hovering position of the tethered lifting multirotor. Multiply the third control gain matrix by the difference between the desired reference speed and the speed of the tethered lifting multirotor to obtain the differential term; Adding the proportional, differential, and integral terms, subtracting the external disturbance force, and then adding the product of mass and gravitational acceleration, yields the desired acceleration of the tethered lifting wing multi-rotor UAV. Multiply the mass of the tethered lifting wing multirotor UAV by the modulus of the desired acceleration to obtain the desired total rotor thrust of the tethered lifting wing multirotor. The desired thrust direction of the tethered lifting multi-rotor is determined based on the desired acceleration and the modulus of the desired acceleration.

6. The method according to claim 1, characterized in that, The functional expression for the desired total controlled torque of the tethered lifting multi-rotor is: ;in, This represents the actual rotational angular velocity of the lifting multi-rotor at the current moment. With the desired rotational angular velocity The difference between them This represents the desired total controlled torque. This represents the upper limit of the expected total controlled torque. , and All of these are control parameters.

7. The method according to claim 6, characterized in that, The desired rotational angular velocity is determined based on the difference between the actual attitude angle and the desired attitude angle of the lifting multi-rotor and the angle feedback matrix.

8. A control system for a tethered lifting wing multirotor unmanned aerial vehicle based on interference adaptive control, characterized in that, include: The disturbance observation module is used to estimate the external disturbance force and external disturbance torque in real time based on the mass, speed and rotational angular velocity of the tethered lifting multi-rotor. The yaw control module is used to determine the desired yaw angle of the tethered lifting multirotor based on the yaw angle of the tethered lifting multirotor and the external disturbance torque. The position control module is used to determine the desired total rotor thrust and thrust direction of the tethered lifting wing multi-rotor based on the actual hovering position, speed, desired hovering position and external disturbance force of the tethered lifting wing multi-rotor, and to transform the thrust direction into the desired attitude angle of the tethered lifting wing multi-rotor. The attitude control module is used to determine the desired total controlled torque of the tethered lifting multi-rotor based on the desired attitude angle and desired yaw angle of the tethered lifting multi-rotor. The power control module is used to enable the tethered lifting wing multi-rotor UAV to adaptively align with the wind direction during hovering and flight, in response to the desired total rotor thrust and total controlled torque.

9. A tethered lifting wing multi-rotor unmanned aerial vehicle, characterized in that, Including memory and processor; A memory for storing computer programs, the computer programs including program instructions; A processor is configured to execute the program instructions to cause the tethered lifting wing multirotor unmanned aerial vehicle to perform the steps of a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The system is coded with program instructions that enable one or more programmable processors to be configured to perform either a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control system as described in claim 8, or a disturbance-adaptive tethered lifting wing multirotor unmanned aerial vehicle control method as described in any one of claims 1 to 7.

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