A method and system for anti-sway control of a drone parachute

Abstract

This invention discloses an anti-sway control method and system for a drone descent device, belonging to the field of drone technology. Addressing the problem of load swaying during single-rope descent, this invention uses the descent device's sensor module to acquire sway state information such as the load's sway angle, rate of change of sway angle, and rope tension, identifying the sway phase of the load. Short-stroke rope retraction is performed near the maximum sway angle, and short-stroke rope release is performed near the lowest point, introducing equivalent damping to the load's sway and consuming sway energy. Anti-sway control is superimposed on the conventional descent commands as an additional control quantity and executed in parallel with the main task. This invention does not rely on drone flight control attitude adjustment or multi-rope differential mechanisms; it achieves closed-loop anti-sway using only the single-rope descent device's own retraction and release capabilities. It has a simple structure, strong engineering feasibility, and is suitable for descent operations with large loads, long ropes, and complex environments.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically relating to an anti-sway control method and system for a UAV descent device. Background Technology

[0002] With the widespread application of drones in areas such as material delivery, emergency rescue, engineering operations, and air-ground coordination, the demand for sling transport and rappelling operations using ropes or descent devices is constantly increasing. During rappelling, hovering, or transfer, the load is usually connected to the drone via a flexible rope. Under the influence of factors such as flight disturbances, environmental wind fields, and changes in rope length, swaying is prone to occur. Swaying not only reduces operational accuracy but may also increase the risk of the load colliding with surrounding obstacles, and in severe cases, even affect flight safety.

[0003] In existing technologies, various control schemes have been proposed to address the swaying problem of hoisted loads. One type of scheme mainly suppresses swaying indirectly by adjusting the attitude, trajectory, or acceleration of the UAV itself; another type of scheme introduces multi-rope differential adjustment, complex actuators, or visual positioning devices into the hoisting mechanism to reduce swaying by correcting load posture deviations. These schemes can suppress swaying under certain conditions, but they usually suffer from problems such as complex system coupling, high difficulty in mechanism implementation, and high control costs. Especially in the scenario of single-rope descent, it is often difficult to balance structural simplification, engineering feasibility, and compatibility with the main descent task.

[0004] Furthermore, most existing publicly available drone descent devices or rappelling systems focus on functions such as rope deployment and retrieval, speed limiting protection, ground contact detection, and top-reach protection. Their control logic is primarily used to ensure the safety and reliability of the rappelling process, lacking an active anti-sway mechanism for the critical phase of the swing. In single-rope rappelling conditions, if only traditional rope deployment and retrieval control is relied upon without considering the swing phase characteristics, the load swing is easily amplified by disturbances, making it difficult to effectively suppress during the rappelling process.

[0005] Therefore, it is necessary to propose an anti-sway control method and system for single-rope descent scenarios of UAVs. Without relying on complex multi-rope differential mechanisms or large-scale adjustments to the UAV flight control attitude, the method can effectively suppress the sway of the load and ensure the normal execution of the main descent task by using only the descent device's own rope extension and retraction capabilities during the critical phase of the swing. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an anti-sway control method and system for unmanned aerial vehicle (UAV) descent devices. This invention solves the problem that existing single-rope descent devices cannot effectively suppress load swaying during descent. By controlling the descent device to perform short-stroke extension and retraction adjustments on the rope during the critical phase of swaying, equivalent damping is introduced to the load swaying, thereby consuming swaying energy and suppressing load swaying.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an anti-sway control method for a drone descent device, wherein the descent device is installed below the drone and connected to a sling via a single rope, and the anti-sway control method includes:

[0008] Obtain the swing state information of the load under rope suspension, the swing state information including the swing angle, the rate of change of the swing angle and the rope tension;

[0009] Based on the swing state information, determine whether the load has entered the anti-swing control state and identify the current swing phase of the load;

[0010] Anti-swing control quantities are calculated based on the swing phase, and the anti-swing control quantities include the rope reeling / releasing direction, reeling / releasing speed, and reeling / releasing stroke.

[0011] The descent device is controlled to adjust the rope in a short stroke according to the anti-sway control amount. The rope adjustment introduces equivalent damping to the swing of the load, so as to reduce the swing energy and suppress the swing of the load.

[0012] Feedback updates are performed on the adjusted oscillation state to form a closed-loop anti-oscillation control.

[0013] Furthermore, the swing state information is acquired by the sensor module of the descent device; the sensor module is located at the end of the rope and includes an inertial measurement unit and a tension sensor.

[0014] Furthermore, the inertial measurement unit is used to measure the attitude angle of the load relative to the vertical direction in order to obtain the swing angle and the rate of change of the swing angle of the load.

[0015] Furthermore, the tension sensor is used to measure changes in rope tension, and the control module of the descent device assists in determining the swing phase of the load based on the periodic change characteristics of the rope tension.

[0016] Furthermore, determining whether the load has entered the anti-swing control state based on the swing state information specifically involves:

[0017] When the swing angle of the load is detected to exceed the preset swing angle threshold, anti-swing control is activated to put the load into anti-swing control state.

[0018] Furthermore, identifying the current swing phase of the hoist includes:

[0019] When the rate of change of the swing angle approaches zero and the swing angle reaches a local extreme value, it is determined that the load is at the position of maximum swing angle;

[0020] When the rate of change of the swing angle reaches its extreme value or the rope tension reaches its peak value, the load is determined to be at the lowest point of swing.

[0021] Further, the calculation of the anti-sway control quantity based on the swing phase includes:

[0022] When it is determined that the load is within a set range near the maximum swing angle position, the anti-swing control quantity for performing the rope winding operation is calculated, so as to control the drive motor of the descent device to perform the rope winding operation;

[0023] When it is determined that the load is within a set range near the lowest swing point, the anti-swing control quantity used to perform the rope release operation is calculated to control the drive motor of the descent device to perform the rope release operation.

[0024] Furthermore, the single adjustment stroke of the short-stroke release and retrieval adjustment is less than the basic rope release stroke per unit time during normal rappelling; the single adjustment stroke satisfy:

[0025]

[0026] in, The swing angle of the load relative to the vertical direction. The reference length of the rope. For the current moment The length of the rope, To maximize the allowable single adjustment stroke, This is the proportionality coefficient. This is a function that takes the smaller value.

[0027] Furthermore, the anti-sway control and the normal descent control of the descent device are executed in parallel:

[0028] The rope deployment and take-off data generated by the anti-sway control is superimposed on the normal descent data as an additional control quantity to generate the final control command. The degree of influence of the rope deployment and take-off data generated by the anti-sway control on the normal descent data is adjusted by a collaborative weighting coefficient. The collaborative weighting coefficient is dynamically adjusted according to the stage and swing state of the normal descent task, so as to suppress the hoisting swing in real time without changing the main objective of the descent task.

[0029] The present invention also provides a drone descent system with anti-sway control function, the system being a single-rope descent structure, comprising:

[0030] A rope reeling mechanism is used to perform rope reeling and deployment operations;

[0031] A drive motor is used to drive the rope winding and unwinding mechanism to perform rope winding and unwinding operations;

[0032] The sensor module is used to collect information on the swing state of the hoisted load.

[0033] The control module is connected to both the drive motor and the sensor module, and is configured as follows:

[0034] The swing state information of the hoisted load is obtained through the sensor module;

[0035] Based on the swing state information, determine whether the load has entered the anti-swing control state and identify the swing phase of the load;

[0036] Calculate the anti-swing control quantity based on the swing phase;

[0037] The drive motor is controlled to perform short-stroke winding and unwinding adjustments on the rope according to the anti-sway control amount;

[0038] Feedback updates are performed on the adjusted oscillation state to form a closed-loop anti-oscillation control.

[0039] Compared with existing technologies, this invention has the following advantages: This invention addresses single-rope descent scenarios by relocating anti-sway control from the flight control side or multi-rope differential mechanism side to the descent actuator side. It achieves sway energy attenuation through phase-triggered short-stroke rope retraction and extension adjustments. This not only reduces the complexity of the system structure and control coupling but also effectively suppresses load sway without significantly affecting the primary descent task, demonstrating significant engineering application value. This invention does not rely on complex multi-rope differential mechanisms or large-scale attitude adjustments by UAV flight control. Its simple control structure and strong engineering feasibility make it suitable for complex conditions such as large loads, long ropes, descent transfers, and ground-to-air docking. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the UAV descent device in an embodiment of the present invention;

[0041] Figure 2 A flowchart illustrating the implementation of the anti-sway control method for a drone descent device provided in this embodiment of the invention;

[0042] Figure 3 This is a schematic diagram illustrating the relationship between the hoisting swing phase and anti-swing control in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0045] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0046] like Figure 1 As shown, in this embodiment, the descent device is installed below the drone and connected to the sling via a single rope. The descent device 1 includes a rope retraction mechanism 2, a drive motor 3, a control module 4, a rope 5, and a sensor module 6.

[0047] Among them, the rope release and retrieval mechanism 2 is used to realize the active release and retrieval of the rope, the drive motor 3 is used to drive the rope release and retrieval mechanism 2 to run, the control module 4 is used to execute the anti-sway control logic and output corresponding control commands, and the sensor module 6 is set at the end of the rope or between the descent device and the load to collect information reflecting the swing state of the load.

[0048] In this embodiment, the sensor module 6 includes a tension sensor and an inertial measurement unit (IMU). The tension sensor is used to acquire rope tension information, and the inertial measurement unit (IMU) is used to acquire the attitude information of the load or the end of the rope relative to the vertical direction.

[0049] During rappelling or hovering, the load can be regarded as a swinging system suspended below the drone by flexible ropes. Its swing is mainly manifested as periodic angular changes around the vertical direction, and this swing is easily excited and gradually amplified by wind disturbance, drone attitude perturbation, or during rappelling.

[0050] like Figure 2 As shown in the figure, this embodiment provides an anti-sway control method for a drone descent device. The specific implementation steps of the anti-sway control method are as follows.

[0051] Step S1: Acquisition of oscillation state information

[0052] The swing state information of the hoisted load is acquired in real time by sensor module 6. The swing state information includes: the swing angle of the hoisted load relative to the vertical direction, the rate of change of the swing angle, and the rope tension and its change. Among them, the swing angle and the rate of change of the swing angle are measured by inertial measurement unit (IMU), and the rope tension is measured by tension sensor.

[0053] Step S2: Identification and Judgment of Oscillation State

[0054] The control module 4 processes the collected swing state information to determine whether the load has entered the anti-swing control state, and further identifies the swing direction and swing amplitude.

[0055] In this embodiment, when the swing angle is detected to exceed the preset swing angle threshold, it is determined that the load needs to enter the anti-swing control state and the anti-swing control is started; when the swing angle is less than the preset swing angle threshold, the anti-swing control is not executed, and only normal descent or hovering control is executed.

[0056] Step S3: Determine the oscillation phase

[0057] Control module 4 determines the current swing phase of the load based on the swing angle change rate or rope tension change characteristics. Specifically, when the swing angle change rate approaches zero and the swing angle reaches a local extreme value, the load is determined to be at the maximum swing angle position; when the swing angle change rate reaches an extreme value or the rope tension reaches a peak value, the load is determined to be at the lowest swing point position.

[0058] Step S4: Calculation of anti-swing control quantity

[0059] The control module 4 calculates the corresponding anti-swing control quantity based on the current swing phase and swing amplitude. The anti-swing control quantity includes at least the rope reeling / unleashing direction, rope reeling / unleashing speed, and rope reeling / unleashing stroke length.

[0060] In this embodiment, the anti-sway control adopts an energy-consuming control strategy. Specifically, when the load is determined to be within a set range near the maximum swing angle, an anti-sway control quantity is calculated to perform the rope-retracting operation, thereby controlling the drive motor of the descent device 1 to perform the rope-retracting operation. When the load is determined to be within a set range near the lowest swing point, an anti-sway control quantity is calculated to perform the rope-releasing operation, thereby controlling the drive motor of the descent device 1 to perform the rope-releasing operation. Through this method, the active retraction and release of the rope 5 creates a counter-effect with the swing of the load, thereby consuming the kinetic and potential energy of the load.

[0061] Step S5: The decelerator performs anti-sway adjustment.

[0062] The control module 4 outputs control commands to the drive motor 3, causing the rope retrieval mechanism 2 to perform corresponding short-stroke retrieval adjustments according to the anti-sway control amount. The single stroke of the short-stroke retrieval adjustment is less than the basic rope release stroke per unit time of the descent device 1 during normal descent, to avoid significantly affecting the normal descent process.

[0063] Step S6: Closed-loop feedback and iterative control

[0064] After completing one anti-sway adjustment, the control module 4 continues to collect the swing state information of the load and repeats steps S2 to S5 according to the updated swing state. Through multiple iterative adjustments, the swing amplitude of the load is gradually reduced until the swing angle is less than the preset swing angle threshold, thereby achieving stable suspension or stable descent.

[0065] In this embodiment, the UAV sling-rope system is approximated as a planar pendulum system, ignoring the higher-order effects of rope mass and air resistance, and only considering the motion characteristics under small swing angles. Therefore, the dynamic model of the sling swing can be expressed as:

[0066]

[0067] in, The swing angle of the load relative to the vertical direction. For the equivalent length of the rope, It is the acceleration due to gravity. The speed at which the descent device's rope is extended or retracted is given. As the model shows, changes in rope length directly affect the load's sway state, providing a theoretical basis for achieving anti-sway control through rope adjustment via the descent device.

[0068] Sensor module 6, located at the end of the rope, acquires the hoisting attitude angle data and calculates the swing angle and the rate of change of swing angle.

[0069]

[0070] In discrete control cycle The rate of change of the pendulum angle can then be further calculated:

[0071]

[0072] in: , These are the acceleration components of the IMU in the horizontal and vertical directions. To control the cycle.

[0073] In an alternative implementation, rope tension information is incorporated to aid in determining the hoisting swing phase. Rope tension It can be represented as:

[0074]

[0075] The control module 4 assists in determining the swing phase by detecting the extreme points of tension changes. When the tension reaches its peak value, the load is close to the lowest swing point, and when the tension reaches its trough value, the load is close to the maximum swing angle position.

[0076] A phase-triggered control strategy is adopted. When the load swing is detected to meet one of the following conditions, the anti-sway control is triggered:

[0077]

[0078] in, This is the preset swing angle threshold.

[0079] In this embodiment, the anti-sway control is not achieved by correcting the load attitude deviation through multi-rope differential adjustment, nor by suppressing the sway through the attitude adjustment of the UAV body. Instead, for the single-rope descent scenario, the rope is finely adjusted in a short stroke during the critical phase of the sway, so that the rope length change and the load sway form an energy-consuming coupling effect, thereby achieving anti-sway control without significantly affecting the main descent task.

[0080] After the anti-sway control is triggered, control module 4 calculates the rope retraction and extension control speed based on the swing phase. Its control law is:

[0081]

[0082] Where: a negative sign indicates pulling in the rope, and a positive sign indicates releasing the rope; This is the anti-sway control gain coefficient. Through the above control method, the active retraction and release of the rope creates a counter-effect to the swaying of the load, thereby consuming the kinetic and potential energy of the load.

[0083] In this embodiment, to explain the anti-swing mechanism of the phase-triggered rope retraction control from an energy perspective, the hoisting-rope system is considered as a variable-length pendulum system. Let the equivalent length of the rope be... The lifting capacity is The swing angle is The acceleration due to gravity is Then the tangential dynamic equation of the system can be expressed as:

[0084]

[0085] The mechanical energy of the hoisting swing system consists of kinetic energy and gravitational potential energy, and can be expressed as:

[0086]

[0087] Taking the derivative of the above mechanical energy expression with respect to time, we get:

[0088]

[0089] Substituting the system's tangential dynamic equations into the above equation, we get...

[0090]

[0091] Substituting the values, we can obtain the rate of change of the system's mechanical energy as:

[0092]

[0093] Therefore, the rate of change of mechanical energy is related to the rope's release and take-up speed. And it is closely related to the phase of the oscillation.

[0094] When the load is near the extreme value of the swing angle, we have:

[0095]

[0096] At this point, the rate of change of mechanical energy is approximately:

[0097]

[0098] Because near the extreme value of the swing angle there is ,therefore:

[0099]

[0100] If the rope-reeling operation is performed at this time, then:

[0101]

[0102] Therefore, we can conclude that:

[0103]

[0104] This indicates that performing the rope-reeling operation near the extreme value of the swing angle can reduce the mechanical energy of the system, thereby suppressing the swing.

[0105] When the load is near the lowest point of swing, we have:

[0106]

[0107] At this point, the rate of change of mechanical energy is approximately:

[0108]

[0109] Near the lowest point of the swing, the angular velocity of the load is usually not zero, and the following holds true:

[0110]

[0111] If the rope-releasing operation is performed at this time, then:

[0112]

[0113] Therefore, we can also conclude that:

[0114]

[0115] This indicates that performing the rope release operation near the lowest point of the swing can also reduce the mechanical energy of the system, thereby suppressing the swing.

[0116] Furthermore, under small angle conditions, we have:

[0117]

[0118] Therefore, the rate of change of mechanical energy can also be approximated as:

[0119]

[0120] As can be seen from the above formula, near the extreme value of the swing angle, due to The first option is dominant, so take it. This ensures that the mechanical energy is reduced; near the lowest point of the swing, due to The second option is dominant, so we take it. This also ensures a reduction in mechanical energy. Therefore, the formula proves that the phase-triggered control strategy of "retracting the rope near the extreme value of the swing angle and releasing the rope near the lowest point of the swing" employed in this invention enables the system to meet the following requirements.

[0121]

[0122] This enables energy-consuming anti-sway control.

[0123] To avoid interference with the normal descent process due to anti-swing control, this embodiment limits the anti-swing adjustment to short-stroke control. Single adjustment stroke. satisfy:

[0124]

[0125] in: This is the reference length for the rope; For the current moment The length of the rope; This is the maximum permissible single adjustment stroke; This is the proportionality coefficient; To achieve a smaller function value, the above constraints prevent over-adjustment in long-rope working conditions.

[0126] In this embodiment, anti-sway control is not a simple replacement for the descent control of the descent device, but rather an additional control quantity executed in conjunction with the main descent task. The rope deployment and take-up data generated by the anti-sway control are superimposed on the normal descent data as an additional control quantity to generate the final control command. A collaborative weighting coefficient is introduced to adjust the degree of influence of the rope deployment and take-up data generated by the anti-sway control on the normal descent data. This collaborative weighting coefficient is dynamically adjusted according to the stage and swing state of the normal descent task to suppress the hoisting swing in real time without changing the main descent task objective.

[0127] set up The basic rope release and take-up speed instructions given for the rappelling mission. To add velocity for anti-sway control, the final rope control command executed by the descent device can be expressed as:

[0128]

[0129] in, This is the collaborative weighting coefficient, with a value range of [value range missing]. This is used to adjust the degree of influence of anti-sway control on the main task control. When the system is in the middle of normal descent and the swaying is significant... Take the larger value; when the system is approaching the target location, in the ground contact phase, or when the main task has a high priority. Take the smaller value or zero.

[0130] Furthermore, to avoid introducing unnecessary disturbances in anti-sway control under small swing conditions, additional anti-sway control is only activated when the load swing angle exceeds a preset threshold, i.e.:

[0131]

[0132] in, The original additional velocity output by the anti-pendulum algorithm. The maximum allowable value for the additional anti-swing velocity. This is a limiting function. To ensure the descent actuator operates within permissible limits, a total limiting process can also be applied to the final rope control command:

[0133]

[0134] Therefore, anti-sway control is only a local modification to the basic cable descent control, and it can suppress the sway of the load in real time without significantly changing the average descent speed and the target rope length.

[0135] In a preferred embodiment, the stroke length of the short-stroke rope retraction or release is adaptively adjusted according to the swing angle amplitude of the load. When the swing angle amplitude is large, the stroke length of a single short-stroke adjustment is increased accordingly; when the swing angle amplitude is small, the stroke length is decreased accordingly. Simultaneously, the stroke length of the short-stroke adjustment is inversely correlated with the current rope length to avoid over-adjustment under long rope conditions, thereby maintaining a stable anti-swing control effect under different load masses and different rope lengths.

[0136] In this embodiment, the anti-sway control method and the normal descent control of the descent device are executed in parallel. While the control module outputs the basic descent control command, it also superimposes the short-stroke rope release and retraction command generated by the anti-sway control, so that the descent device can suppress the sway of the load in real time without affecting the overall descent speed. This coordinated control method is suitable for application scenarios with high stability requirements, such as descent transfer and ground-to-air docking.

[0137] As can be seen from the above embodiments, the anti-sway control method for UAV descent devices provided by the present invention has at least the following technical effects: it can achieve anti-sway control by actively retracting and extending the descent device rope, reducing dependence on the UAV flight control system; it effectively suppresses the swing of the suspended load during the descent process, preventing the swing from accumulating and amplifying; the control strategy has a clear structure and low engineering implementation difficulty, and is suitable for large loads and long rope operations; it is particularly suitable for UAV transfer, ground-to-air docking and descent operations in complex environments.

[0138] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0139] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0140] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0141] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0142] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for anti-sway control of a drone descent device, wherein the descent device is installed below the drone and connected to a rigging device via a single rope, characterized in that, The anti-sway control method includes: Obtain the swing state information of the load under rope suspension, the swing state information including the swing angle, the rate of change of the swing angle and the rope tension; Based on the swing state information, determine whether the load has entered the anti-swing control state and identify the current swing phase of the load; Anti-swing control quantities are calculated based on the swing phase, and the anti-swing control quantities include the rope reeling / releasing direction, reeling / releasing speed, and reeling / releasing stroke. The descent device is controlled to adjust the rope in a short stroke according to the anti-sway control amount. The rope adjustment introduces equivalent damping to the swing of the load, so as to reduce the swing energy and suppress the swing of the load. Feedback updates are performed on the adjusted oscillation state to form a closed-loop anti-oscillation control.

2. The anti-sway control method for a UAV descent device according to claim 1, characterized in that, The swing state information is acquired by the sensor module of the descent device; the sensor module is located at the end of the rope and includes an inertial measurement unit and a tension sensor.

3. The anti-sway control method for a UAV descent device according to claim 2, characterized in that, The inertial measurement unit is used to measure the attitude angle of the load relative to the vertical direction in order to obtain the swing angle and the rate of change of the swing angle.

4. The anti-sway control method for a UAV descent device according to claim 2, characterized in that, The tension sensor is used to measure changes in rope tension, and the control module of the descent device helps determine the swing phase of the load based on the periodic changes in rope tension.

5. The anti-sway control method for a UAV descent device according to claim 1, characterized in that, The step of determining whether the load has entered the anti-swing control state based on the swing state information specifically involves: When the swing angle of the load is detected to exceed the preset swing angle threshold, anti-swing control is activated to put the load into anti-swing control state.

6. The anti-sway control method for a UAV descent device according to claim 1, characterized in that, The identification of the current swing phase of the hoist includes: When the rate of change of the swing angle approaches zero and the swing angle reaches a local extreme value, it is determined that the load is at the position of maximum swing angle; When the rate of change of the swing angle reaches its extreme value or the rope tension reaches its peak value, the load is determined to be at the lowest point of swing.

7. The anti-sway control method for a UAV descent device according to claim 6, characterized in that, The calculation of the anti-swing control quantity based on the swing phase includes: When it is determined that the load is within a set range near the maximum swing angle position, the anti-swing control quantity for performing the rope winding operation is calculated, so as to control the drive motor of the descent device to perform the rope winding operation; When it is determined that the load is within a set range near the lowest swing point, the anti-swing control quantity used to perform the rope release operation is calculated to control the drive motor of the descent device to perform the rope release operation.

8. The anti-sway control method for a UAV descent device according to claim 1, characterized in that, The single adjustment stroke of the short-stroke release and retrieval adjustment is less than the basic rope release stroke per unit time during normal rappelling; the single adjustment stroke satisfy: in, The swing angle of the load relative to the vertical direction. The reference length of the rope. For the current moment The length of the rope, To maximize the allowable single adjustment stroke, This is the proportionality coefficient. This is a function that takes the smaller value.

9. The anti-sway control method for a UAV descent device according to claim 1, characterized in that, The anti-sway control and the normal descent control of the descent device are executed in parallel: The rope deployment and take-off data generated by the anti-sway control is superimposed on the normal descent data as an additional control quantity to generate the final control command. The degree of influence of the rope deployment and take-off data generated by the anti-sway control on the normal descent data is adjusted by a collaborative weighting coefficient. The collaborative weighting coefficient is dynamically adjusted according to the stage and swing state of the normal descent task, so as to suppress the hoisting swing in real time without changing the main objective of the descent task.

10. A drone descent system with anti-sway control function, characterized in that, The system is a single-rope rappelling structure, including: A rope reeling mechanism is used to perform rope reeling and deployment operations; A drive motor is used to drive the rope winding and unwinding mechanism to perform rope winding and unwinding operations; The sensor module is used to collect information on the swing state of the hoisted load. The control module is connected to both the drive motor and the sensor module, and is configured as follows: The swing state information of the hoisted load is obtained through the sensor module; Based on the swing state information, determine whether the load has entered the anti-swing control state and identify the swing phase of the load; Calculate the anti-swing control quantity based on the swing phase; The drive motor is controlled to perform short-stroke winding and unwinding adjustments on the rope according to the anti-sway control amount; Feedback updates are performed on the adjusted oscillation state to form a closed-loop anti-oscillation control.

Images