A constant direction driving system and method for a tethered unmanned aerial vehicle winch torque motor

Abstract

This invention discloses a tethered UAV winch torque motor constant-direction drive winding and unwinding system and method. The system consists of five core modules: a constant-direction drive mechanism powered by a clockwise rotating torque motor; a gear reversing transmission mechanism that transmits power through multi-stage gears; a one-way clutch mechanism that controls power on / off using a one-way bearing; a reversing actuator that uses a servo motor to drive a gear swing arm, which in turn drives the swing arm gear to switch between different meshing positions; and a dual-mode control mechanism that supports manual and automatic dual-mode output control signals to drive the servo motor and complete the switching between winding and unwinding conditions. In the winding condition, the swing arm gear directly drives the winding drum to wind the line, and the winding tension can be directly adjusted by the torque output of the torque motor. In the unwinding condition, the power end idles, and the winding drum is passively unwinded by the UAV, with no reverse mechanical energy feedback to the motor. This solves the technical problems of reverse energy burning out the driver, cable failure caused by mismatched unwinding speed, and gear wear during switching between conditions in traditional solutions.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to a tethered UAV winch torque motor constant-direction drive cable take-up and release system and method. Background Technology

[0002] Tethered drones, as special aircraft capable of ultra-long-endurance aerial operations, are widely used in fields such as emergency communication, high-altitude reconnaissance, meteorological monitoring, and forest fire prevention. During their flight, they require continuous power supply and signal transmission from the ground end to the air end through tethered cables. The winch, as the core actuator for retrieving and extending the tethered cable, directly determines the operational safety and endurance of the tethered drone through its cable retrieval stability, tension control accuracy, and operational reliability.

[0003] Torque motors, due to their adjustable output torque and ability to operate at low speeds for extended periods, are a popular choice for powering tethered winches. They allow for direct control of the cable tension by adjusting the output torque, adapting to the different tension requirements of tethered cables under various working conditions. However, existing tethered winches driven by torque motors generally suffer from the following technical drawbacks: Reverse energy feedback can easily damage hardware: During the cable release process, the torque motor needs to reverse to cooperate with the cable release. At this time, the winding drum is dragged by the drone, which causes the torque motor to reverse passively. The torque motor becomes a generator, and the mechanical energy generated in the reverse direction will be fed back to the motor driver. At best, it will cause the motor to heat up extra and reduce its service life. At worst, it will directly burn out the drive circuit and cause equipment failure.

[0004] Poor matching of line release speed can easily lead to cable failure: If the torque motor is controlled by electronic control to actively reverse the line release, the motor speed adjustment accuracy is difficult to match the real-time ascent speed of the drone. If the motor speed is too fast, it will cause over-release of the line, and the cable will become loose, tangled, or grooved inside the winch. If the motor speed is too slow, it will increase the cable tension, which may drag the drone and affect its flight stability, or even break the tether line and cause the drone to crash out of control.

[0005] Switching between operating conditions can easily lead to component wear: Traditional winch winding requires simultaneous adjustment of motor rotation and transmission path when switching between winding and unwinding. There is a large difference in speed and direction of movement between the gears to be engaged, which can easily cause gear tooth impact during switching. Long-term operation can lead to tooth surface wear, tooth breakage, and reduced equipment lifespan.

[0006] Therefore, there is an urgent need to develop a new torque motor driven cable take-up and release system to improve the operational reliability and scenario adaptability of tethered drone winches. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to provide a tethered UAV winch torque motor constant direction drive take-up and release system and method, which can switch the take-up and release modes without adjusting the motor direction, thereby solving the technical problems of reverse energy feedback burning the driver, mismatched release speed easily causing cable failure, and easy tooth breakage when switching modes. At the same time, it supports manual / automatic dual-mode control, improving the reliability of winch operation and scene adaptability.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows: A tethered unmanned aerial vehicle (UAV) winch torque motor constant-direction drive cable take-up and release system includes: The constant-direction drive mechanism includes a torque motor, the output end of which is fixedly connected to a drive gear, and the torque motor maintains a constant rotation in a single clockwise direction throughout the entire process; The gear reversing transmission mechanism includes a rocker arm gear, a first gear, an upper gear, a lower gear, and a second gear. The upper gear and the lower gear mesh with each other, the second gear and the lower gear are concentrically and fixedly connected, and the second gear is coaxially and fixedly driven with the winding drum. The one-way clutch mechanism includes a one-way bearing. The first gear is coaxially assembled with the upper gear through the one-way bearing. When the first gear rotates clockwise, the one-way bearing idles and does not drive the upper gear. When the first gear rotates counterclockwise, the one-way bearing locks and drives the upper gear to rotate synchronously. The reversing actuator includes a servo motor and a gear swing arm. The swing arm gear is rotatably mounted on the end of the gear swing arm. The servo motor drives the gear swing arm to swing, thereby causing the swing arm gear to switch meshing between the second gear and the first gear. The dual-mode control mechanism is electrically connected to the servo motor and is used to manually or automatically output control signals to drive the servo motor to switch between take-up and let-out modes.

[0009] Preferably, in the winding condition, the swing arm gear meshes with the second gear, and the torque motor drives the second gear and the winding drum to wind the wire clockwise via the drive gear and the swing arm gear. The winding tension is directly adjusted by the torque output of the torque motor. The upper gear rotates counterclockwise synchronously with the lower gear. The one-way bearing is in the unlocked state, and the first gear remains stationary. During the wire laying operation, the swing arm gear meshes with the first gear, and the torque motor drives the first gear to rotate freely. The winding drum is passively laid counterclockwise by being dragged by the tethered drone, and there is no reverse mechanical energy feedback to the torque motor.

[0010] Preferably, the dual-mode control mechanism includes: The manual control unit is a remote control PWM signal module that directly outputs signals to drive the servo motor to swing. The automatic control unit includes a fixed pulley, a movable pulley, a return spring, and a sliding potentiometer. The tether wire is wound around the fixed pulley and the movable pulley. The movable pulley is linked to the sliding end of the sliding potentiometer. The return spring is used to reset the movable pulley. The sliding potentiometer outputs a corresponding PWM signal to the servo motor according to the tension of the tether wire. The switching unit is a remote control relay used for the physical switching between the manual control unit and the automatic control unit.

[0011] Preferably, under the line-laying condition, when the rotation speed of the upper gear driven by the passive rotation of the winding drum is greater than the rotation speed of the first gear driven by the torque motor, the torque motor outputs a damping torque to limit the ascent speed of the tethered UAV and the line-laying speed of the winding drum.

[0012] A method for controlling the constant-directional drive of a winch torque motor for tethered unmanned aerial vehicles (UAVs) to reel in and release cables, based on the aforementioned system, includes the following steps: The control torque motor maintains a constant clockwise rotation throughout the entire process, and the power is continuously output through the drive gear at the output end of the torque motor; The dual-mode control mechanism outputs control signals to drive the servo motor to move, causing the gear swing arm to swing, so that the swing arm gear switches between two positions: meshing with the second gear and meshing with the first gear. When the swing arm gear switches to the meshing position with the second gear, the power is transmitted to the second gear through the drive gear and the swing arm gear, which drives the winding drum fixed coaxially with the second gear to rotate clockwise to complete the winding. The winding tension is directly adjusted by the output torque of the torque motor. When the swing arm gear switches to the meshing position with the first gear, the power is transmitted to the first gear through the drive gear and the swing arm gear. When the first gear rotates clockwise, the one-way bearing rotates freely, and the winding drum is passively rotated counterclockwise by the tethered drone to complete the wire unloading. There is no reverse mechanical energy feedback to the torque motor.

[0013] Preferably, during the winding process, the number of rotations of the winding drum is counted in real time, and the actual winding diameter of the current winding drum is obtained by combining the initial winding diameter and the diameter of the tether wire. The target output torque is generated by combining the preset winding tension and the transmission efficiency coefficient, and the output torque of the torque motor is dynamically adjusted according to the target output torque.

[0014] Preferably, when the winding drum is passively rotated counterclockwise by being dragged by the tethered drone, causing the upper gear meshing with the lower gear to rotate clockwise at a speed greater than the clockwise rotation speed of the first gear driven by the torque motor, the torque motor outputs damping torque by using a dynamic gradient matching rule. The dynamic gradient matching rule includes: real-time acquisition of three parameters: the real-time speed difference between the upper gear and the first gear, the wire release speed of the winding drum, and the real-time tension of the tethering wire; obtaining the damping torque coefficient of the current adaptation; and then adjusting the drive current of the torque motor to output a corresponding damping torque.

[0015] Preferably, when the output control signal drives the servo motor to move, it includes: The control path is switched to the manual control unit via a remote relay, and the remote PWM signal module directly outputs a signal to drive the servo motor to swing. Alternatively, the control path can be switched to the automatic control unit via a remote control relay. The tether wire is wound around a fixed pulley and a movable pulley. The movable pulley is linked to the sliding end of the linear potentiometer. The linear potentiometer outputs a corresponding PWM signal to drive the servo motor according to the real-time tension of the tether wire.

[0016] Preferably, the remote control relay adopts a dual-contact interlocking structure. When performing a switching action, the corresponding contact of the original conduction path is first disconnected, and the corresponding contact of the target path is closed after a delay of 20~50ms. At the same time, the power supply to the servo motor input signal is temporarily cut off during the delay interval. After the remote control relay completes the switching action, it collects the output signal levels of the manual control unit and the automatic control unit, as well as the signal source of the servo motor input terminal, to verify whether the current conduction path is consistent with the target path of the switching command. If the verification does not match, a second switching action is triggered. If the switching verification fails twice in a row, an alarm signal is output to the remote control terminal and the current safe path is locked.

[0017] Preferably, the PWM signal output of the sliding potentiometer is equipped with a dual calibration mechanism: Factory pre-calibration: Adjust the tension of the tether wire to three calibration points: no-load 0 value, rated working tension, and maximum safe tension. Record the output resistance of the sliding potentiometer, the displacement of the movable pulley, and the duty cycle of the corresponding output PWM signal for each calibration point, and store them as a reference calibration mapping table. Dynamic self-calibration: When the cumulative operation reaches the preset cumulative time, the current output resistance value of the sliding potentiometer is automatically collected under no-load conditions and compared with the no-load calibration point of the reference calibration mapping table. If the deviation exceeds the set value, the offset of the entire mapping table is automatically corrected.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention addresses the industry pain points of existing tethered drone winch torque motor drive solutions by combining an innovative design of "constant directional power input + mechanical reversing transmission + one-way clutch chain breakage + dual-mode redundant control" to achieve the switching of the torque motor between cable reeling and unloading modes without reversing throughout the entire process.

[0019] (1) This invention breaks through the traditional winch winding and unwinding technology that requires the motor to switch between forward and reverse rotation. The torque motor maintains a constant clockwise rotation throughout the entire process. During the unwinding operation, the transmission chain between the power end and the load end is broken through the one-way bearing. When the winding drum is passively unwinding, it will not cause the torque motor to reverse. This completely avoids the industry problem of the torque motor being passively reversed to generate electricity and the reverse mechanical energy feedback burning out the driver. At the same time, it eliminates the problem of the motor overheating. The service life of the motor and driver can be significantly improved, and the fault-free operation time of the equipment is greatly extended. (2) During the line laying operation, the winding drum is passively rotated by the tethered drone. The line laying speed is completely synchronized with the drone's ascent speed. There is no need for the electric control torque motor to actively reverse the line laying, thus avoiding faults such as over-laying, cable loosening and tangling, and excessive tension breaking the tethered line caused by the mismatch between the motor speed and the drone speed. It is suitable for the line laying needs of the tethered drone in all working conditions from hovering to maximum ascent speed, and the cable failure rate can be significantly reduced.

[0020] (3) When the first gear is stationary during the take-up condition, the swing arm gear is driven by the torque motor to maintain constant and uniform rotation. When switching from take-up to unwind condition, the relative speed difference between the two gear surfaces is stable and controllable, which solves the problem of gear impact caused by excessive speed difference and direction difference of the meshing gears in the traditional scheme. The gear wear rate can be significantly reduced, and the mechanical reliability of the equipment during long-term operation is greatly improved.

[0021] (4) The system supports manual mode with manual remote control switching and automatic mode with tension linkage. The dual-path switching is achieved through physically interlocked remote control relays to avoid signal conflicts. The manual mode is suitable for special scenarios such as equipment debugging, operation in complex obstacle areas, and emergency intervention. The automatic mode can automatically match the drone's lifting and lowering status according to the tension of the mooring line. It can adapt to scenarios such as regular fixed-point cruise and long-term high-altitude operation without manual intervention. Compared with the winch with a single control mode, the scope of application is greatly improved.

[0022] (5) No additional braking components are required. The automatic speed limit when the UAV is overspeeding can be achieved by simply reusing the existing one-way clutch transmission structure: When the UAV overspeeds and the speed of the upper gear exceeds the speed of the first gear, the one-way bearing is automatically locked, and the torque motor outputs damping torque to limit the wire release speed. At the same time, the dynamic gradient matching rule is adopted to adaptively adjust the damping size according to the speed difference, wire release speed, and real-time tension. This will not interfere with the normal flight of the UAV, and will also avoid the safety risks of the cable leaving the groove and the UAV exceeding the cable length due to excessive wire release.

[0023] (6) During the winding process, the actual winding diameter is calculated in real time by the number of rotations of the winding drum, and the output torque of the torque motor is dynamically adjusted. The winding tension control accuracy can reach ±5%, ensuring that the winding is neat and without looseness. At the same time, it is equipped with a dual calibration mechanism of factory pre-calibration + dynamic self-calibration. It can automatically correct the signal drift caused by long-term wear of potentiometer without manual disassembly and debugging. The control accuracy of automatic mode is stable for a long time.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0025] Figure 1 This is an overall structural diagram of the take-up and unwinding system according to an embodiment of the present invention; Figure 2 This is a first internal structure diagram of the take-up and unwinding system according to an embodiment of the present invention; Figure 3 This is a second internal structure diagram of the take-up and unwinding system according to an embodiment of the present invention; Figure 4 This is a block diagram of the dynamic control logic for the take-up tension of the constant-direction drive winch according to an embodiment of the present invention. Figure 5 This is a block diagram of the logic for dynamic adjustment of multi-parameter fusion damping torque of the constant-direction drive winch according to an embodiment of the present invention. Figure 6 This is a block diagram of the safety control logic for dual-contact interlocking path switching and verification of the remote control relay according to an embodiment of the present invention. Figure 7 This is a block diagram of the dual-calibration control logic for the PWM output of the sliding potentiometer according to an embodiment of the present invention. Figure 8 This is a block diagram of the logic for converting the resistance of a sliding potentiometer to a segmented nonlinear PWM circuit, according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached diagram: 1. Winding drum; 2. Torque motor; 3. Drive gear; 4. Swing arm gear; 5. First gear; 6. Upper gear; 7. Lower gear; 8. Second gear; 9. One-way bearing; 10. Servo motor; 11. Gear swing arm; 12. Fixed pulley; 13. Moving pulley; 14. Return spring; 15. Straight sliding potentiometer; 16. First base; 17. Second base; 18. First side plate; 19. Second side plate; 20. Third side plate; 21. Aluminum column; 22. Servo motor mount; 23. Bearing mount; 24. Tie wire. Detailed Implementation

[0027] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0028] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0030] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0031] See Figures 1 to 3 Example 1: The present invention provides a tethered UAV winch torque motor constant direction drive take-up and unwinding system, including a constant direction drive mechanism, a gear reversing transmission mechanism, a one-way clutch mechanism, a winding drum 1, a reversing execution mechanism and a dual-mode control mechanism; The constant direction drive mechanism includes a torque motor 2, the output end of which is fixedly connected to a drive gear 3, and the torque motor 2 maintains a constant rotation in a single clockwise direction throughout the entire process; The gear reversing transmission mechanism includes a rocker arm gear 4, a first gear 5, an upper gear 6, a lower gear 7, and a second gear 8. The upper gear 6 and the lower gear 7 mesh with each other, and the second gear 8 is concentrically and fixedly connected to the lower gear 7. The second gear 8 is coaxially and fixedly driven with the winding drum 1. The one-way clutch mechanism includes a one-way bearing 9. The first gear 5 is coaxially assembled with the upper gear 6 through the one-way bearing 9. When the first gear 5 rotates clockwise, the one-way bearing 9 idles and does not drive the upper gear 6. When the first gear 5 rotates counterclockwise, the one-way bearing 9 locks and drives the upper gear 6 to rotate synchronously. The reversing actuator includes a servo motor 10 and a gear swing arm 11. The swing arm gear 4 is rotatably mounted on the end of the gear swing arm 11. The servo motor 10 drives the gear swing arm 11 to swing, thereby causing the swing arm gear 4 to switch meshing between the second gear 8 and the first gear 5. The dual-mode control mechanism is electrically connected to the servo motor 10 and is used to manually or automatically output control signals to drive the servo motor 10 to switch between take-up and let-out modes.

[0032] Specifically, the core design concept of this system is to break through the logic of traditional winches requiring motor rotation switching between forward and reverse directions for winding and unwinding. The torque motor 2 rotates only in a single clockwise direction throughout the entire process. The switching between winding and unwinding modes is achieved through a combination of "mechanical reversing transmission + one-way clutch". This avoids the industry pain points of energy feedback burning out the driver when the torque motor 2 reverses and the mismatch between the unwinding speed and the drone's status. The overall operating principle can be broken down into modules as follows: As the sole power source, the constant-direction drive mechanism ensures that the torque motor 2 maintains a constant clockwise rotation throughout the entire process. The power is continuously output through the fixed drive gear 3 at the output end. There is no need to adjust the motor direction or modify the basic control logic of the driver. At the same time, it is compatible with the characteristics of the torque motor 2, which can be stalled for a long time and whose output torque is easy to adjust, thus providing a foundation for precise control of the winding tension.

[0033] Gear transmission relationship: The upper gear 6 and the lower gear 7 are in constant mesh. The lower gear 7, the second gear 8, and the winding drum 1 are coaxially rigidly fixed. Power is transmitted to the second gear 8, which can directly drive the winding drum 1 to rotate synchronously. The first gear 5 and the upper gear 6 are coaxially assembled through a one-way bearing 9. The one-way bearing 9 is locked only when the first gear 5 rotates counterclockwise, driving the upper gear 6 to rotate synchronously. If the first gear 5 rotates clockwise, the one-way bearing 9 will idle, and power will not be transmitted to the upper gear 6.

[0034] Mechanical reversing logic: The reversing actuator is powered by the servo motor 10, which drives the gear swing arm 11 to swing, allowing the swing arm gear 4 at the end to switch between two meshing positions: meshing with the second gear 8 corresponds to the take-up condition, and meshing with the first gear 5 corresponds to the unwind condition. The working condition is changed through pure mechanical position switching, which has fast response speed and high reliability.

[0035] Servo motor 10 drives the rocker arm gear 4 to switch to the position where it meshes with the second gear 8: The torque motor 2 rotates clockwise, driving the drive gear 3 and the swing arm gear 4 in sequence. The swing arm gear 4 rotates counterclockwise, driving the second gear 8 and the winding drum 1 to rotate clockwise simultaneously to complete the winding. The winding tension can be precisely controlled by adjusting the output torque of the torque motor 2.

[0036] In this state, the lower gear 7 rotates clockwise with the winding drum 1, driving the meshing upper gear 6 to rotate counterclockwise synchronously. The one-way bearing 9 is in the unlocked state, and the first gear 5 remains stationary, eliminating the gear speed difference for subsequent working condition switching and avoiding gear impact.

[0037] Servo motor 10 drives the rocker arm gear 4 to switch to the position where it meshes with the first gear 5: The torque motor 2 rotates clockwise, driving the drive gear 3 and the swing arm gear 4 in sequence. The swing arm gear 4 rotates counterclockwise, driving the first gear 5 to rotate clockwise. At this time, the one-way bearing 9 is idling, and the power is not transmitted to the upper gear 6 and the downstream winding drum 1 transmission chain. The winding drum 1 is passively rotated counterclockwise by the rising tethered drone to release the line, and there will be no problems of over-release or cable tangling caused by the motor's active drive. At the same time, the winding drum 1 will not drive the torque motor 2 to reverse, and there is no reverse mechanical energy feedback to the driver, thus avoiding the risk of driver damage.

[0038] If the drone ascends too quickly, and the rotational speed of the upper gear 6 driven by the winding drum 1 exceeds the rotational speed of the first gear 5 driven by the torque motor 2, the torque motor 2 can output a damping torque to limit the wire release speed, thus preventing the drone from ascending too fast and the cable from coming loose.

[0039] The system supports both manual and automatic control modes, which can be physically switched via a remote relay. Manual mode: The servo motor 10 is driven to swing directly by the output PWM signal of the remote control. The operator can switch the line take-up and lay-out mode according to the drone's operating status. It is suitable for equipment debugging and special operating scenarios.

[0040] Automatic mode: The tension detection component consists of a fixed pulley 12, a movable pulley 13, a return spring 14, and a sliding potentiometer 15. Changes in the tension of the tether line 24 cause the movable pulley 13 to move, which in turn causes the potentiometer to slide and output a corresponding PWM signal. It automatically matches the drone status: when the drone rises and the tension of the tether line 24 increases, it automatically switches to the line-laying mode; when the drone descends and the tension of the tether line 24 decreases, it automatically switches to the line-retrieving mode. It can adapt to the drone's rising and falling movements without manual intervention.

[0041] In one possible embodiment, during the winding operation, the swing arm gear 4 meshes with the second gear 8, and the torque motor 2 drives the second gear 8 and the winding drum 1 to wind the wire clockwise via the drive gear 3 and the swing arm gear 4. The winding tension is directly adjusted by the torque output torque of the torque motor 2. During the wire laying operation, the swing arm gear 4 meshes with the first gear 5, and the torque motor 2 drives the first gear 5 to rotate freely. The winding drum 1 is passively laid counterclockwise by being dragged by the tethered drone, and there is no reverse mechanical energy feedback to the torque motor 2.

[0042] Specifically, this embodiment is based on a combined design of "constant directional power input + mechanical transmission path switching + one-way clutch chain breaking". Under the premise that the torque motor 2 does not change its rotation direction throughout the entire process, it can achieve precise switching between the two working conditions of take-up and unwinding by simply adjusting the meshing object of the swing arm gear 4. At the same time, it solves the industry pain points of traditional winches from the root of the structure. The specific principle is broken down as follows: During the winding process, the swing arm gear 4 meshes with the second gear 8, forming a rigid closed transmission chain: Power transmission path: The torque motor 2, which always rotates clockwise, outputs power to the drive gear 3. The drive gear 3 drives the meshing swing arm gear 4 to rotate counterclockwise. The swing arm gear 4 directly drives the second gear 8 to rotate clockwise. Since the second gear 8 and the winding drum 1 are coaxial and rigidly fixed, the winding drum 1 rotates clockwise synchronously to complete the winding action.

[0043] Direct tension adjustment principle: The entire transmission chain consists of non-slip rigid gear meshing. The output torque of the torque motor 2 has a direct linear relationship with the take-up tension (conforming to the formula: torque motor output torque = take-up tension × current winding diameter of the bobbin ÷ transmission efficiency). Only the drive current of the torque motor 2 needs to be adjusted to directly change the output torque, precisely controlling the take-up tension. This prevents excessive tension from breaking the tether line 24 and insufficient tension from causing the take-up to become loose. It perfectly matches the characteristics of the torque motor 2, which has adjustable output torque and can be locked at low speeds for extended periods.

[0044] During the wire laying process, the swing arm gear 4 switches to mesh with the first gear 5, forming a separate transmission structure where the power end idles and the load end operates independently. Power end idling logic: The torque motor 2 continues to rotate clockwise, and the power is transmitted to the first gear 5 through the drive gear 3 and the swing arm gear 4, causing the first gear 5 to rotate clockwise; at this time, the one-way bearing 9 between the first gear 5 and the upper gear 6 is in the unlocked idling state, and the rotational power of the first gear 5 will not be transmitted to the coaxial upper gear 6. The entire downstream lower gear 7, second gear 8, and winding drum 1 transmission chain are completely disconnected from the power end.

[0045] Passive cable release + no reverse feedback principle: The cable drum 1 has no active power input. It is only passively rotated counterclockwise by the cable when the tethered drone rises and pulls the tether line 24. The cable release speed is completely matched with the drone's ascent speed. This avoids the problems of over-release and cable entanglement caused by the mismatch between the motor speed and the drone speed in traditional electronically controlled reverse cable release. At the same time, since the rotation of the cable drum 1 is not transmitted in reverse to the torque motor 2, the torque motor 2 will not be driven by the load to reverse and become a generator. Therefore, there is no problem of reverse mechanical energy feedback to the driver. Structurally, this avoids the failure of driver burnout and motor overheating.

[0046] In one possible embodiment, see [reference] Figure 2The dual-mode control mechanism includes a manual control unit, an automatic control unit, and a switching unit. The manual control unit is a remote control PWM signal module that directly outputs signals to drive the servo motor 10 to swing. The automatic control unit includes a fixed pulley 12, a movable pulley 13, a return spring 14, and a sliding potentiometer 15. The tethering wire 24 winds around the fixed pulley 12 and the movable pulley 13. The movable pulley 13 is linked to the sliding end of the sliding potentiometer 15. The return spring 14 is used to reset the movable pulley 13. The sliding potentiometer 15 outputs a corresponding PWM signal to the servo motor 10 according to the tension of the tethering wire 24. The switching unit is a remote control relay used for the physical switching between the manual control unit and the automatic control unit.

[0047] Specifically, the dual-mode control mechanism is the central decision-making hub for the take-up and lay-out system. It adapts to different operating scenarios through "manual + automatic" dual control modes, while employing a physical switching mechanism to ensure control reliability. This solves the problems of poor adaptability of a single mode and easy loss of control due to signal conflicts from the control level. The operating principle of each unit is broken down as follows: The manual control unit, with the remote-controlled PWM signal module at its core, belongs to the control chain that requires direct human intervention. Operating logic: Ground operators can issue a reel-in / reel-out switching command via remote controller based on the real-time operation status of the UAV. The remote control PWM signal module converts the manual operation command into a pulse width modulation (PWM) signal that the servo motor 10 can directly recognize. The signal is transmitted directly to the servo motor 10 through an independent channel. The servo motor 10 swings the corresponding angle according to the duty cycle of the PWM signal, driving the swing arm gear 4 to switch the meshing position and complete the operation mode switching.

[0048] Applicable scenarios: Suitable for special scenarios such as equipment debugging, operation in complex obstacle areas, and emergency intervention. The control strategy can be flexibly adjusted manually to avoid judgment errors in special working conditions in automatic mode.

[0049] The automatic control unit is a closed-loop control link for tension-signal conversion, which can automatically match the drone's takeoff and landing status without manual intervention. Structural linkage logic: The tethering line 24 passes through the fixed pulley 12 and the movable pulley 13 that can slide up and down on the frame according to the preset path. The movable pulley 13 is rigidly connected to the sliding end of the straight sliding potentiometer 15 at the same time. The reset spring 14 always applies a downward reset force to the movable pulley 13.

[0050] Signal conversion and control logic: When the tethered drone ascends, the tension of the tether line 24 increases, overcoming the pulling force of the reset spring 14 and pulling the pulley 13 upward, causing the sliding end of the potentiometer 15 to move upward synchronously. The output resistance of the potentiometer changes linearly with the displacement of the sliding end. The supporting circuit converts the resistance change into a PWM signal with a corresponding duty cycle and transmits it to the servo motor 10, driving the servo motor 10 to switch to the line release position. When the drone descends, the tension of the tether line 24 decreases, the reset spring 14 pulls the pulley 13 downward to reset, causing the sliding end of the potentiometer to move downward, and outputting a corresponding PWM signal to drive the servo motor 10 to switch to the line take-up position.

[0051] Applicable scenarios: Suitable for scenarios such as regular fixed-point cruise and long-term high-altitude operation. It can automatically match the drone's lifting and lowering movements, greatly reducing the workload of operators. The control response is directly related to the cable tension, reducing control delay.

[0052] The switching unit uses a remote-controlled relay to achieve physical path switching, ensuring reliable operation in both modes. Operating logic: The remote control relay is equivalent to a mutually exclusive electronic control switch. The operator can send a switching command through the remote control to control the relay to conduct the corresponding control path: either only the signal path from the manual control unit to the servo motor 10 is connected, or only the signal path from the automatic control unit to the servo motor 10 is connected. The two paths are physically interlocked and will never be connected at the same time.

[0053] Design advantages: Completely avoids signal conflict and malfunction of servo motor 10 caused by simultaneous output signals from two control units; the reliability of physical switching is far higher than that of software switching. If one control unit fails, it can immediately switch to the other path to maintain system operation, without the safety risk of the whole machine going out of control.

[0054] This dual-mode design not only covers the operational needs of multiple scenarios, but also ensures the safety of system operation at the control link level, significantly improving the adaptability of the winch compared to a single control mode.

[0055] In one possible embodiment, during the line-laying operation, when the rotation speed of the upper gear 6 driven by the passive rotation of the winding drum 1 is greater than the rotation speed of the first gear 5 driven by the torque motor 2, the torque motor 2 outputs a damping torque to limit the ascent speed of the tethered UAV and the line-laying speed of the winding drum 1.

[0056] Specifically, this design is a purely mechanically triggered safety redundancy mechanism for line-laying operations. It fully reuses the existing one-way clutch transmission structure of the system, without the need for additional sensors or braking components. It can automatically limit the speed when the UAV ascends at excessive speed, thus avoiding the risk of line-laying loss of control at the source. The specific operating principle is as follows: The triggering of this function is based on the inherent characteristics of the one-way clutch mechanism: the first gear 5 and the upper gear 6 are coaxially assembled through the one-way bearing 9. Only when the two show a counterclockwise relative rotation trend, the one-way bearing 9 automatically locks, and the two become a rigid synchronous transmission structure; if the relative rotation trend is clockwise, they remain idle and separated.

[0057] The initial state under the wire feeding condition is as follows: the swing arm gear 4 meshes with the first gear 5, and the torque motor 2 drives the first gear 5 to maintain a constant clockwise rated speed (denoted as V1). At this time, the one-way bearing 9 is in an idle state, and the upper gear 6 is linked with the winding drum 1. When feeding the wire, the drone drags the winding drum 1 to rotate passively, and the upper gear 6 synchronously maintains clockwise rotation with a speed of V2, which is positively correlated with the wire feeding speed of the winding drum 1.

[0058] When the tethered drone suddenly accelerates upward due to factors such as strong airflow lifting and sudden changes in power output, it will pull the winding drum 1 to rotate counterclockwise quickly to release the line. The corresponding clockwise rotation speed V2 of the upper gear 6 will increase rapidly. When V2 > V1, the upper gear 6 will have a counterclockwise relative motion tendency with respect to the first gear 5, which just meets the locking condition of the one-way bearing 9. The one-way bearing 9 will lock automatically, and the upper gear 6 and the first gear 5 will become rigidly connected, and the power chain will be closed again.

[0059] After the one-way bearing 9 is locked, the upper gear 6 needs to drive the first gear 5 to rotate at a speed exceeding the rated speed V1 set by the torque motor 2. The torque motor 2 is in a constant direction and constant torque output state and will actively output a reverse resisting torque (i.e., damping torque). This damping torque is transmitted in reverse through the rigid transmission chain to the upper gear 6, lower gear 7, and winding drum 1, and finally acts on the tether line 24. This can limit the unloading speed of the winding drum 1 to prevent the tether line 24 from becoming loose, tangled, or thrown out of the groove due to excessive unloading speed. It can also limit the drone's ascent speed through the tension of the tether line 24 to prevent the drone from exceeding the maximum unloading length of the tether line 24 or crashing into obstacles out of control.

[0060] The magnitude of the damping torque can be flexibly set in advance by adjusting the rated output torque of the torque motor 2, which can adapt to the operational requirements of different loads and different tensile strengths of the mooring wire 24, and will not cause problems such as excessive damping that breaks the mooring wire 24 or insufficient damping that cannot limit the speed.

[0061] In one possible embodiment, see [reference] Figure 1 and Figure 2 The gear reversing transmission mechanism, the one-way clutch mechanism, and the winding drum 1 are all mounted on the frame assembly. The frame assembly includes a first base 16, a second base 17, a first side plate 18, a second side plate 19, a third side plate 20, and multiple sets of aluminum pillars 21. The servo motor 10 is fixed to the gear swing arm 11 through the servo motor base 22. The two ends of the winding drum 1 are rotated and assembled through the bearing seats 23.

[0062] Specifically, this frame assembly is the mechanical load-bearing base of the entire take-up and unwinding system. It adopts a design concept of "split modularization + standard parts combination". Its core function is to ensure the assembly accuracy and transmission stability of each moving part, while taking into account lightweight, maintainability and scene adaptability. It provides a structural foundation for the reliable realization of the aforementioned functions such as constant direction drive, reversing transmission and working condition switching. The specific principle is broken down as follows: The frame adopts a split assembly structure of "double base + multiple side plates + 21 aluminum columns" instead of the traditional integrated welded / cast frame: The first base 16 and the second base 17 are the bottom bearing units, which directly bear the weight of the entire system. The fixing hole positions of the base can be flexibly adjusted according to the installation scenario (airborne drone, ground base station, vehicle-mounted) to adapt to different installation carriers. At the same time, heavy power components such as the torque motor 2 are preferentially fixed on the first side plate 18, which can lower the center of gravity of the system and reduce vibration during high-speed operation.

[0063] The first side plate 18, the second side plate 19, and the third side plate 20 are functional mounting surfaces, and multiple sets of aluminum columns 21 serve as rigid connection components. The aluminum columns 21 can be flexibly adjusted by changing different length specifications to adjust the distance between the first side plate 18 and the third side plate 20, adapting to gear transmission groups of different modules. There is no need to re-open molds and adjust the frame size, which greatly reduces the cost of customized modification. At the same time, the weight of aluminum components is much lower than that of steel frames, which meets the design requirements of lightweight tethering systems.

[0064] Servo 10 Assembly: Servo 10 is directly fixed to the mounting reference surface of gear swing arm 11 via servo mount 22. The output shaft of servo 10 is directly coaxially connected to the rotation shaft of gear swing arm 11 without intermediate transmission links, completely eliminating transmission play. The rotation angle output by servo 10 can be transmitted to gear swing arm 11 in a 1:1 ratio, ensuring the positional accuracy of swing arm gear 4 when switching between two meshing positions, and preventing problems such as incomplete meshing or position switching failure.

[0065] Assembly of winding drum 1: The two ends of winding drum 1 are rotated and assembled through independent bearing seats 23. The bearing seats 23 are standard universal parts. On the one hand, the coaxiality of winding drum 1 can be accurately calibrated by adjusting the installation position of bearing seats 23, so as to avoid problems such as uneven wear and misaligned cable arrangement during winding. On the other hand, when the bearing wears out, the bearing seat 23 / internal bearing can be directly replaced without disassembling the entire frame or replacing winding drum 1, which greatly reduces the later maintenance cost.

[0066] In one possible embodiment, during the take-up operation, the upper gear 6 rotates counterclockwise synchronously with the lower gear 7, the one-way bearing 9 is in the unlocked state, the first gear 5 remains stationary, and the impact of tooth knocking when the swing arm gear 4 switches meshing is eliminated.

[0067] Specifically, the core cause of gear meshing damage is that the relative speed difference between the tooth surfaces of the two meshing gears is too large, or their relative motion directions are opposite. During meshing, the tooth surfaces undergo rigid collisions, and long-term impacts will lead to tooth surface wear and tooth breakage.

[0068] In this design, when the system needs to switch from the take-up mode to the let-out mode, the servo motor 10 drives the swing arm gear 4 to disengage from the second gear 8 and swing towards the first gear 5 to engage. At this time, the swing arm gear 4 is driven by the torque motor 2 and maintains a constant and uniform rotational state, while the first gear 5 is stationary. When the two mesh, the relative speed difference between the tooth surfaces is stable and controllable. The teeth of the swing arm gear 4 can smoothly engage with the tooth grooves of the first gear 5 and drive it to rotate synchronously. There will be no rigid collision caused by high-speed opposite movement, thus eliminating tooth knocking impact.

[0069] This invention also provides a method for controlling the constant-directional drive of a winch torque motor for reeling in and out of a tethered unmanned aerial vehicle (UAV), based on the above-described system implementation, and comprising the following steps: S1, Constant power output: The control torque motor 2 maintains a constant clockwise rotation throughout the entire process, and the power is continuously output through the drive gear 3 at the output end of the torque motor 2; S2, Working condition switching control: The dual-mode control mechanism outputs control signals to drive the servo motor 10 to move, which in turn drives the gear swing arm 11 to swing, so that the swing arm gear 4 switches between two working positions: meshing with the second gear 8 and meshing with the first gear 5, thereby realizing the switching between the take-up working condition and the unwinding working condition. S3, take-up condition execution: When the swing arm gear 4 switches to the meshing position with the second gear 8, the power is transmitted to the second gear 8 through the drive gear 3 and the swing arm gear 4, which drives the winding drum 1, which is fixed coaxially with the second gear 8, to rotate clockwise to complete the take-up. The take-up tension is directly adjusted by the output torque of the torque motor 2. S4. Execution of wire feeding condition: When the swing arm gear 4 switches to the meshing position with the first gear 5, the power is transmitted to the first gear 5 through the drive gear 3 and the swing arm gear 4. When the first gear 5 rotates clockwise, the one-way bearing 9 idles and does not drive the coaxially assembled upper gear 6 and downstream transmission mechanism. The winding drum 1 is passively rotated counterclockwise by the tethered drone to complete the wire feeding, and there is no reverse mechanical energy feedback to the torque motor 2.

[0070] Specifically, the core design idea of ​​this control method is to break through the traditional technical path of requiring torque motor 2 to switch between forward and reverse rotation for tethered winch cable take-up and release. Through a combination design of "constant directional power output + mechanical transmission path switching + one-way clutch chain breaking", the take-up and release conditions can be switched while torque motor 2 maintains rotation in one direction throughout the entire process. This solves the industry pain points of traditional solutions, such as the energy feedback of torque motor 2 during reverse rotation burning out the driver and the cable tangling caused by the mismatch between the electronic control cable release speed and the state of the UAV. The operating principle of each step is as follows: Principle of constant directional power output: The torque motor 2, as the sole power source, maintains a constant clockwise rotation throughout the entire process. The power is continuously output through the fixed drive gear 3 at the output end. There is no need to adjust the motor's direction of rotation or modify the basic control logic of the driver. At the same time, it is adapted to the characteristics of the torque motor 2, which can be stalled for a long time and whose output torque is easily adjustable, providing a foundation for the subsequent structural design of precise control of winding tension and no reverse energy feedback.

[0071] Operating condition switching control principle: The dual-mode control mechanism outputs drive signals to the servo motor 10, enabling operation mode switching through purely mechanical station switching. This method offers fast response, high reliability, and supports two switching modes. Manual mode: Switch to manual control via remote relay. Operators can directly send PWM signals to drive servo motor 10 to swing through the remote controller. The operator can manually switch the operating mode according to the drone's operating status to adapt to scenarios such as debugging and operation in special obstacle areas. Automatic mode: When switched to automatic control path, the tension change of the tether line 24 causes the movable pulley 13 to move, which in turn drives the direct sliding potentiometer 15 to output the corresponding PWM signal, automatically matching the drone status: when the drone rises and the tension increases, the line release is automatically cut off, and when the drone descends and the tension decreases, the line reeling is automatically cut off, without the need for manual intervention and adapting to conventional operation scenarios.

[0072] The remote control relay adopts a dual-contact physical interlock design to avoid conflict between the two control signals, which could cause the servo motor 10 to malfunction and ensure switching reliability.

[0073] Operating principle of take-up mode: After the swing arm gear 4 switches to mesh with the second gear 8, a rigid closed transmission chain is formed: the power transmission path is "clockwise rotating torque motor 2 → driving gear 3 → swing arm gear 4 (counterclockwise rotation) → second gear 8 (clockwise rotation) → winding drum 1 (synchronous clockwise rotation)", which directly completes the winding action.

[0074] Because the drive chain is a non-slip rigid gear mesh, the output torque of the torque motor 2 and the take-up tension are linearly related (conforming to the formula: target output torque = preset take-up tension × current actual winding diameter of the bobbin / transmission efficiency coefficient). Only the drive current of the torque motor 2 needs to be adjusted to accurately control the take-up tension, so that the pull force will not be too large to break the tether line 24, nor too small to cause the take-up to become loose.

[0075] When the line is being wound up, the lower gear 7, which is coaxial with the second gear 8, rotates clockwise in sync, causing the meshing upper gear 6 to rotate counterclockwise. The one-way bearing 9 is in the unlocked state, and the first gear 5 remains stationary. This eliminates the gear speed difference for subsequent working condition switching and avoids gear impact.

[0076] Execution principle of wire laying operation: After the swing arm gear 4 switches to mesh with the first gear 5, a separate transmission structure of "power end idling + load end independent" is formed: Power end idling logic: The torque motor 2 continues to rotate clockwise. After the power is transmitted to the first gear 5, the one-way bearing 9 between the first gear 5 and the upper gear 6 is in the unlocked idling state. The power will not be transmitted to the downstream winding drum 1 transmission chain, thus avoiding over-unloading and cable tangling problems caused by the motor's active drive. Passive line feeding + no reverse feedback logic: The winding drum 1 has no active power input. It is passively rotated counterclockwise to feed the line by being dragged by the ascending tethered drone. The line feeding speed is perfectly matched with the drone's ascent speed. At the same time, the rotation of the winding drum 1 will not be transmitted in reverse to the torque motor 2. The torque motor 2 will not be driven by the load to reverse and become a generator. There is no problem of reverse mechanical energy feedback to the driver. Structurally, this avoids the failure of driver burnout and motor overheating.

[0077] If the drone ascends too quickly, and the rotational speed of the upper gear 6 driven by the winding drum 1 exceeds the rotational speed of the first gear 5 driven by the torque motor 2, the one-way bearing 9 will automatically lock, and the torque motor 2 will output damping torque to limit the wire release speed, thus preventing the drone from ascending too fast and the cable from coming loose, forming an automatic safety redundancy.

[0078] In one possible embodiment, see [reference] Figure 4 During the winding process, the number of rotations of the winding drum 1 is counted in real time. The actual winding diameter of the winding drum 1 is obtained by combining the initial winding diameter and the wire diameter of the tie wire 24. The target output torque is generated by combining the preset winding tension and transmission efficiency coefficient. The output torque of the torque motor 2 is dynamically adjusted according to the target output torque. The target output torque is calculated as: preset take-up tension × actual diameter of the current winding drum / transmission efficiency coefficient.

[0079] Specifically, this solution is a method for precise tension control of a tethered drone's constant-direction drive winch during cable retrieval. The core objective is to maintain stable cable tension throughout the retrieval process, preventing excessive tension from breaking the tether line 24 or insufficient tension from causing the cable to loosen, become tangled, or develop grooves. The specific principle can be broken down layer by layer: According to the torque formula in classical mechanics: torque = force × lever arm, in the case of winch winding, the torque output by the winding drum 1 directly corresponds to the product of the winding tension and the winding drum diameter. At the same time, there will be a fixed proportion of power loss in the gear transmission, bearing friction and other links. Therefore, the magnitude of the winding tension can be controlled in reverse by adjusting the output torque of the torque motor 2.

[0080] During the winding process, the number of cable layers on the winding drum 1 will continuously increase, and the actual winding diameter (the radius from the rotation center of the winding drum 1 to the surface of the outermost cable) will dynamically increase: The system pre-loads two fixed parameters: the initial diameter of the winding drum 1 when unloaded and the nominal diameter of the tie wire 24.

[0081] During the winding stage, the encoder counts the cumulative number of rotations of the winding drum 1 in real time. Since the actual winding diameter of the winding drum 1 increases by approximately one wire diameter for each turn of cable, the current actual winding diameter can be quickly calculated without the need for additional distance sensors. This solution is low in cost and highly reliable.

[0082] Incorporating transmission loss compensation, the target torque output required by torque motor 2 is calculated using a fixed formula: Target output torque = preset take-up tension × actual winding diameter of the current bobbin / transmission efficiency coefficient; Preset take-up tension: The optimal tension value set in advance based on the material and load-bearing requirements of the tethering line 24; Transmission efficiency coefficient: A fixed value obtained through pre-calibration is used to compensate for power losses in gear meshing, bearing friction, and other processes, ensuring that the actual torque acting on the winding drum 1 after the transmission chain loss meets the tension requirements.

[0083] During the winding process, the actual winding diameter continuously increases. If the output torque of the torque motor 2 remains fixed, the winding tension will continuously decrease as the winding diameter increases. Therefore, based on the real-time calculated current winding diameter, the drive current of the torque motor 2 is continuously and dynamically adjusted to synchronously match the output torque of the corresponding size, so that the winding tension is kept stable at the preset value throughout the process. The tension control accuracy can reach ±5%, which is suitable for the high-frequency winding and unwinding and stable operation requirements of tethered drones.

[0084] In one possible embodiment, step S4 further includes a damping speed limiting sub-step: when the winding drum 1 is passively rotated counterclockwise by being dragged by the tethered drone, causing the upper gear 6 meshing with the lower gear 7 to rotate clockwise at a speed greater than the clockwise rotation speed of the first gear 5 driven by the torque motor 2, the torque motor 2 is controlled to output a damping torque to limit the ascent speed of the tethered drone and the unloading speed of the winding drum 1.

[0085] In one possible embodiment, see [reference] Figure 5 When the torque motor 2 outputs damping torque, it adopts a dynamic gradient matching rule: real-time acquisition of three parameters: the real-time speed difference between the upper gear 6 and the first gear 5, the wire release speed of the winding drum 1, and the real-time tension of the tethering wire 24, to obtain the damping torque coefficient that is currently suitable, and then outputting a corresponding damping torque by adjusting the drive current of the torque motor 2. Wherein, the damping torque coefficient = k1 × real-time speed difference + k2 × wire laying speed + k3 × tension deviation value, and k1, k2, and k3 are pre-calibrated scenario coefficients.

[0086] Specifically, the above is the damping speed limiting adaptive adjustment scheme for the constant-direction drive winch of a tethered drone under the condition of line laying. The core purpose is to achieve precise speed limiting under overspeed conditions without interfering with the normal flight of the drone or damaging the tether line 24, and to solve the problem of poor adaptability of the fixed damping torque. The operating logic can be decomposed into layers: This rule only applies to the line-laying condition: when the tethered drone accelerates upward, it drags the winding drum 1 to rotate passively, causing the clockwise speed of the upper gear 6 to exceed the rated clockwise speed of the first gear 5 driven by the torque motor 2. At this time, the one-way bearing 9 will automatically lock, and the torque motor 2 will need to output a reverse damping torque to limit the line-laying speed. This rule is used to dynamically calculate and adapt the damping magnitude to the current working condition.

[0087] Unlike schemes that use a fixed damping coefficient, this rule selects three core parameters directly related to the damping effect as adjustment inputs to avoid deviations caused by adjusting a single parameter: The real-time speed difference between the upper gear 6 and the first gear 5 directly reflects the degree of overspeeding of the drone. The larger the difference, the more serious the overspeeding, and the greater the damping torque required. The wire feeding speed of winding drum 1 reflects the current wire feeding speed. The higher the speed, the greater the risk of the cable coming loose or falling out of the groove. It is necessary to match the corresponding damping strength. Tether 24 real-time tension: Used for safety restraint to prevent excessive damping that could cause the tension of tether 24 to exceed its tensile limit and break, or insufficient damping that could not limit the speed. The tension deviation value is the difference between the real-time tension and the preset safety tension threshold.

[0088] The real-time damping torque coefficient is calculated using a linear weighted formula: Damping torque coefficient = k1 × real-time speed difference + k2 × wire laying speed + k3 × tension deviation value, where k1, k2, and k3 are weighting coefficients pre-calibrated for different operating scenarios (such as high-altitude strong wind scenarios, low-altitude light load scenarios, etc.). Finally, the system adjusts the drive current of torque motor 2 according to the calculated damping torque coefficient, and outputs a damping torque that matches the current state to achieve adaptive adjustment.

[0089] This solution ensures that the drone is not affected by damping during normal operation, can quickly respond to speed limit when overspeeding, and avoids overload of the tether line 24, greatly improving the safety of the laying operation and adaptability to multiple scenarios.

[0090] In one possible embodiment, step S2 can be implemented in either manual or automatic mode. In manual mode, the control path is switched to the manual control unit via the remote relay, and the remote PWM signal module directly outputs a signal to drive the servo motor 10 to swing, allowing the operator to manually switch between take-up and let-out modes. Automatic mode: The control path is switched to the automatic control unit via the remote control relay. The tether line 24 is wound around the fixed pulley 12 and the movable pulley 13. The movable pulley 13 is linked to the sliding end of the direct sliding potentiometer 15. The direct sliding potentiometer 15 outputs a corresponding PWM signal to drive the servo motor 10 according to the real-time tension of the tether line 24. The working condition is automatically switched according to the ascent and descent state of the tethered drone: When the tethered drone rises and the tension of the tether line 24 increases, causing the movable pulley 13 to slide upward, the mode is automatically switched to the line release mode; when the tethered drone descends and the tension of the tether line 24 decreases, causing the movable pulley 13 to slide downward under the reset action of the return spring 14, the mode is automatically switched to the line reeling mode.

[0091] In one possible embodiment, see [reference] Figure 6 The remote control relay adopts a dual-contact interlocking structure. When performing the switching action, the corresponding contact of the original conduction path is first disconnected, and the corresponding contact of the target path is closed after a delay of 20~50ms. At the same time, the power supply of the input signal of the servo motor 10 is temporarily cut off during the delay interval to avoid the servo motor 10 from malfunctioning due to the simultaneous input of two control signals during the switching transition phase, thus ensuring the uniqueness and accuracy of the path switching. After the remote control relay completes the switching action, it collects the output signal levels of the manual control unit and the automatic control unit, as well as the signal source of the servo motor 10 input terminal, to verify whether the current conduction path is consistent with the target path of the switching command. If the verification does not match, a second switching action is triggered. If the switching verification fails twice in a row, an alarm signal is output to the remote control terminal and the current safety path is locked to avoid loss of control of the working condition caused by the path switching error.

[0092] Specifically, this mechanism is a path reliability assurance design for the dual-mode control system (manual / automatic control mode switching) of tethered UAV winches. The core objective is to resolve the conflict and malfunction risks during the switching of the two control signals, forming a complete reliability closed loop from the two levels of timing protection and fault tolerance verification. The specific principle can be broken down into two parts: (1) Conflict prevention principle during the switching transition phase The remote control relay adopts a dual-contact interlocking hardware structure, coupled with triple protection logic of "break before make + timing buffer + temporary power failure", to fundamentally prevent two signals from being input to the servo motor 10 at the same time. Upon receiving the switching command, the first step is to completely disconnect the contacts of the current conductive path, thus physically cutting off the input source of the original control signal. Set a delay buffer period of 20~50ms: on the one hand, wait for the residual charge in the original path to be completely released and the contact state to be completely stable; on the other hand, temporarily cut off the overall signal power supply of the servo motor 10 during the delay interval to create a "blank window" with no signal input for the servo motor 10. Even if there is a slight timing deviation in the contact action, the servo motor 10 will not receive a conflict signal. After the delay ends, the contact of the target path is closed to complete the mode switch, ensuring that the servo motor 10 can only receive one control signal at any time, avoiding conflicting PWM signals that could cause the servo motor 10 to swing at the wrong angle or fail to switch operating conditions.

[0093] (2) Fault tolerance principle after switching After the switching action is completed, a multi-level verification and fault redundancy mechanism is added to avoid uncontrolled operation caused by hardware failure: After the switching action is completed, three verification signals are collected simultaneously: the output level of the manual control unit, the output level of the automatic control unit, and the actual signal source received by the input terminal of the servo motor 10. The current conduction path is cross-compared with the target path of the switching command to see if they are consistent. If the verification fails, it indicates a fault such as contact sticking or poor contact, and a second switching action will be triggered immediately for retry; If two consecutive switching attempts fail, the relay is deemed to have an unrecoverable hardware fault. In this case, a two-level safety strategy is implemented: first, a fault alarm signal is sent to the ground remote control terminal to prompt the operator to intervene; second, the currently used safety path is immediately locked, and all switching commands are stopped to avoid the risk of loss of control due to mismatch between the cable reeling and laying conditions and the UAV's flight status caused by incorrect path switching, such as cable breakage or entanglement.

[0094] In one possible embodiment, see [reference] Figure 7 The PWM signal output of the sliding potentiometer 15 is equipped with a dual calibration mechanism: Factory pre-calibration: Adjust the tension of the tether wire 24 to three calibration points: no-load 0 value, rated working tension, and maximum safe tension. Record the output resistance of the sliding potentiometer 15, the displacement of the movable pulley 13, and the duty cycle of the corresponding output PWM signal for each calibration point, and store them as a reference calibration mapping table. Dynamic self-calibration: When the system accumulates a preset cumulative time (e.g., 10 hours), it automatically collects the current output resistance value of the sliding potentiometer 15 under no-load conditions and compares it with the no-load calibration point of the reference calibration mapping table. If the deviation exceeds 2%, it automatically corrects the offset of the overall mapping table to avoid output errors caused by long-term wear and displacement of the sliding potentiometer 15.

[0095] Specifically, this mechanism is a signal accuracy assurance design for the automatic control mode of the tethered UAV winch. Its core function is to solve the signal output deviation problem caused by the sliding potentiometer 15, as the core component of tension-signal conversion, due to manufacturing assembly tolerances and long-term wear / loosening during operation. It forms an accuracy closed loop from two dimensions: initial factory calibration and dynamic operation calibration. Theoretically, the correspondence between "tether tension - movable pulley displacement - potentiometer resistance - PWM signal duty cycle" for the linear potentiometer 15 is linear. However, due to uncertainties in the production process, such as individual component tolerances, frame assembly clearances, and spring force dispersion, the actual correspondence for each device has slight deviations. Therefore, pre-calibration at the factory is required to eliminate individual errors. Three key feature calibration points covering the entire range were selected: no-load 0 tension (corresponding to the lowest position of the movable pulley 13, which is the physical reference starting point of the entire range), rated working tension (corresponding to the midpoint of the tension range most commonly used in daily operations, which determines the response accuracy of switching between normal working conditions), and maximum safe tension (corresponding to the upper limit of the range, which is the critical threshold for triggering emergency laying, and is directly related to operational safety). In a laboratory environment, the tension of the tethering line 24 was precisely adjusted to three calibration points. Simultaneously, the actual output resistance of the sliding potentiometer 15, the actual displacement of the movable pulley 13, and the duty cycle of the PWM signal output after circuit conversion were measured and recorded for each point. A unique reference calibration mapping table for each device was generated to replace the general theoretical formula as the basis for signal conversion, ensuring that the tension signal conversion accuracy in automatic mode meets the design requirements at the time of delivery.

[0096] After the equipment has been in operation for a long time, the sliding contacts of the linear potentiometer 15 will wear due to repeated friction, and the linkage structure of the movable pulley 13 may become slightly loose. Both of these factors will cause the original reference mapping table to shift as a whole, resulting in tension judgment errors. Therefore, a periodic dynamic self-calibration mechanism is designed to correct the deviation online. The unloaded zero-tension state is selected as the unified benchmark for dynamic calibration: in this state, the tether line 24 has no tension, the movable pulley 13 returns to the initial lowest position under the action of the return spring 14, the physical benchmark is stable and is not affected by the working scene or load state. Every time the system accumulates a preset running time (e.g., 10 hours), it automatically triggers an unloaded calibration: it collects the actual output resistance value of the sliding potentiometer 15 under the current state and compares it with the unloaded calibration point value in the reference calibration mapping table. If the deviation exceeds 2%, it is determined that the mapping table has shifted. The system automatically uses the currently measured unloaded resistance value as the new reference starting point and shifts and corrects all the correspondences in the entire mapping table. It can eliminate the drift error caused by long-term operation without manual disassembly and debugging, and avoid the problems of untimely switching of working conditions and inaccurate tension control caused by signal deviation.

[0097] This dual calibration mechanism eliminates the need for additional hardware sensors, ensuring that the signal conversion accuracy of the sliding potentiometer 15 remains within acceptable limits. This reduces production and debugging costs, decreases maintenance workload, and improves the reliability of automatic control mode.

[0098] In one possible embodiment, see [reference] Figure 8When the resistance signal of the sliding potentiometer 15 is converted into a PWM signal, a piecewise nonlinear mapping rule is used: When the tension of the mooring line 24 is in the range of 0~30% of the rated tension, the adjustment slope of the PWM duty cycle with the tension change is 1% / N tension unit, which reduces the micro-motion frequency of the servo motor 10 and reduces losses. When the tension is in the range of 30% to 80% of the rated tension, the adjustment slope is 3% / N tension unit to match the working condition switching response speed under normal operation. When the tension is above 80% of the rated tension range, the adjustment slope is 5% / N tension unit to improve the response speed of the servo motor 10 under abnormal tension and quickly switch to the wire release mode to avoid breaking the mooring line 24.

[0099] Specifically, this rule is a signal conversion optimization strategy in the automatic control mode of the tethered UAV winch. The core design idea is to break through the limitations of the traditional single linear mapping. Based on the operating characteristics of the tension range of the tethered line 24, the mapping slope of "tension change - PWM duty cycle change" is set differently, while taking into account three core requirements: the service life of the servo motor 10, the response speed under normal working conditions, and the safety redundancy under abnormal working conditions. (1) 0~30% of rated tension with low slope range This range corresponds to a low-load state where the tether cable is slightly loose, the drone is hovering, or experiencing slow ascent and descent within a small range. In this state, there is no need for rapid switching of operating conditions. Setting a low adjustment slope of 1% / N tension units ensures that minor tension fluctuations and slight cable swaying will not cause the PWM duty cycle to reach the servo motor 10's action threshold. This prevents frequent micro-movements of the servo motor 10 and the potentiometer, effectively reducing mechanical wear and extending component lifespan.

[0100] (2) 30%~80% of rated tension with slope range This range corresponds to the commonly used tension range for normal drone take-off and landing operations, and is the routine working segment with the most frequent changes in operating conditions. A moderate adjustment slope of 3% / N tension units is set, allowing tension changes to be promptly converted into PWM signals with the corresponding duty cycle. This drives the servo motor 10 to respond quickly, matching the drone's normal take-off and landing speed. This prevents both delayed line release that pulls the drone and delayed line retraction that causes the cable to become loose and tangled, ensuring smooth operation during routine tasks.

[0101] (3) High slope range of rated tension above 80% This range corresponds to an abnormal state where the tension is close to the safety threshold. This is generally caused by the drone being lifted by strong airflow and a sudden and rapid increase in power output. It belongs to a high-risk range where safety must be prioritized. By setting a high adjustment slope of 5% / N tension units, even a slight increase in tension will trigger a rapid change in the PWM duty cycle. Servo 10 can switch to the cable release mode in a very short time, quickly releasing the cable to reduce tension and preventing safety accidents such as the tension exceeding the tensile limit of the tether line 24, resulting in breakage and loss of drone control.

[0102] In one possible embodiment, step S3 further includes a non-impact switching pre-step: under the winding condition, the lower gear 7, which is concentrically fixed with the second gear 8, rotates clockwise synchronously with the winding drum 1, driving the upper gear 6, which meshes with the lower gear 7, to rotate counterclockwise synchronously. The one-way bearing 9 is in the unlocked state, the first gear 5 remains stationary, and there is no tooth knocking impact when the swing arm gear 4 switches from the position of the second gear 8 to the position of the first gear 5.

[0103] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A tethered unmanned aerial vehicle (UAV) winch torque motor constant-direction drive cable take-up and release system, characterized in that, include: The constant-direction drive mechanism includes a torque motor, the output end of which is fixedly connected to a drive gear, and the torque motor maintains a constant rotation in a single clockwise direction throughout the entire process; The gear reversing transmission mechanism includes a rocker arm gear, a first gear, an upper gear, a lower gear, and a second gear. The upper gear and the lower gear mesh with each other, the second gear and the lower gear are concentrically and fixedly connected, and the second gear is coaxially and fixedly driven with the winding drum. The one-way clutch mechanism includes a one-way bearing. The first gear is coaxially assembled with the upper gear through the one-way bearing. When the first gear rotates clockwise, the one-way bearing idles and does not drive the upper gear. When the first gear rotates counterclockwise, the one-way bearing locks and drives the upper gear to rotate synchronously. The reversing actuator includes a servo motor and a gear swing arm. The swing arm gear is rotatably mounted on the end of the gear swing arm. The servo motor drives the gear swing arm to swing, thereby causing the swing arm gear to switch meshing between the second gear and the first gear. The dual-mode control mechanism is electrically connected to the servo motor and is used to manually or automatically output control signals to drive the servo motor to switch between take-up and let-out modes.

2. The system according to claim 1, characterized in that, During the winding operation, the swing arm gear meshes with the second gear, and the torque motor drives the second gear and the winding drum to wind the wire clockwise via the drive gear and the swing arm gear. The winding tension is directly adjusted by the torque output of the torque motor. The upper gear rotates counterclockwise synchronously with the lower gear. The one-way bearing is in the unlocked state, and the first gear remains stationary. During the wire laying operation, the swing arm gear meshes with the first gear, and the torque motor drives the first gear to rotate freely. The winding drum is passively laid counterclockwise by being dragged by the tethered drone, and there is no reverse mechanical energy feedback to the torque motor.

3. The system according to claim 1, characterized in that, The dual-mode control mechanism includes: The manual control unit is a remote control PWM signal module that directly outputs signals to drive the servo motor to swing. The automatic control unit includes a fixed pulley, a movable pulley, a return spring, and a sliding potentiometer. The tether wire is wound around the fixed pulley and the movable pulley. The movable pulley is linked to the sliding end of the sliding potentiometer. The return spring is used to reset the movable pulley. The sliding potentiometer outputs a corresponding PWM signal to the servo motor according to the tension of the tether wire. The switching unit is a remote control relay used for the physical switching between the manual control unit and the automatic control unit.

4. The system according to claim 1, characterized in that, During the line-laying operation, when the speed of the upper gear driven by the passive rotation of the winding drum is greater than the speed of the first gear driven by the torque motor, the torque motor outputs a damping torque, which limits the ascent speed of the tethered drone and the line-laying speed of the winding drum.

5. A method for controlling the constant-directional drive of a winch torque motor for reeling in and out of a tethered unmanned aerial vehicle (UAV), implemented based on the system described in any one of claims 1-4, characterized in that... Includes the following steps: The control torque motor maintains a constant clockwise rotation throughout the entire process, and the power is continuously output through the drive gear at the output end of the torque motor; The dual-mode control mechanism outputs control signals to drive the servo motor to move, causing the gear swing arm to swing, so that the swing arm gear switches between two positions: meshing with the second gear and meshing with the first gear. When the swing arm gear switches to the meshing position with the second gear, the power is transmitted to the second gear through the drive gear and the swing arm gear, which drives the winding drum fixed coaxially with the second gear to rotate clockwise to complete the winding. The winding tension is directly adjusted by the output torque of the torque motor. When the swing arm gear switches to the meshing position with the first gear, the power is transmitted to the first gear through the drive gear and the swing arm gear. When the first gear rotates clockwise, the one-way bearing rotates freely, and the winding drum is passively rotated counterclockwise by the tethered drone to complete the wire unloading. There is no reverse mechanical energy feedback to the torque motor.

6. The method according to claim 5, characterized in that, During the winding process, the number of rotations of the winding drum is counted in real time. The actual winding diameter of the current winding drum is obtained by combining the initial winding diameter and the diameter of the tether wire. The target output torque is generated by combining the preset winding tension and the transmission efficiency coefficient. The output torque of the torque motor is dynamically adjusted according to the target output torque.

7. The method according to claim 5, characterized in that, When the winding drum is passively rotated counterclockwise by being dragged by the tethered drone, and the speed at which the upper gear meshing with the lower gear rotates clockwise is greater than the speed at which the first gear driven by the torque motor rotates clockwise, the dynamic gradient matching rule is used to control the output damping torque of the torque motor. The dynamic gradient matching rule includes: real-time acquisition of three parameters: the real-time speed difference between the upper gear and the first gear, the wire release speed of the winding drum, and the real-time tension of the tethering wire; obtaining the damping torque coefficient of the current adaptation; and then adjusting the drive current of the torque motor to output a corresponding damping torque.

8. The method according to claim 5, characterized in that, When the output control signal drives the servo motor to move, it includes: The control path is switched to the manual control unit via a remote relay, and the remote PWM signal module directly outputs a signal to drive the servo motor to swing. Alternatively, the control path can be switched to the automatic control unit via a remote control relay. The tether wire is wound around a fixed pulley and a movable pulley. The movable pulley is linked to the sliding end of the linear potentiometer. The linear potentiometer outputs a corresponding PWM signal to drive the servo motor according to the real-time tension of the tether wire.

9. The method according to claim 8, characterized in that, The remote control relay adopts a dual-contact interlocking structure. When performing a switching action, it first disconnects the corresponding contact of the original conduction path, and then closes the corresponding contact of the target path after a delay of 20~50ms. At the same time, it temporarily cuts off the power supply to the servo motor's input signal during the delay interval. After the remote control relay completes the switching action, the output signal levels of the manual control unit and the automatic control unit, as well as the signal source of the servo motor input terminal, are collected to verify whether the current conduction path is consistent with the target path of the switching command. If the verification fails, a second switching action is triggered. If the verification fails twice in a row, an alarm signal is output to the remote control and the current safe passage is locked.

10. The method according to claim 8 or 9, characterized in that, The PWM signal output of the sliding potentiometer is equipped with a dual calibration mechanism: Factory pre-calibration: Adjust the tension of the tether wire to three calibration points: no-load 0 value, rated working tension, and maximum safe tension. Record the output resistance of the sliding potentiometer, the displacement of the movable pulley, and the duty cycle of the corresponding output PWM signal for each calibration point, and store them as a reference calibration mapping table. Dynamic self-calibration: When the cumulative operation reaches the preset cumulative time, the current output resistance value of the sliding potentiometer is automatically collected under no-load conditions and compared with the no-load calibration point of the reference calibration mapping table. If the deviation exceeds the set value, the offset of the entire mapping table is automatically corrected.

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