RU2819974C1 - System for automatic winding-unwinding of cable of tethered uav - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to process equipment for automatic winding-unwinding of a cable on a drum with further use of the cable for unmanned aerial vehicle tether. System for automatic winding-unwinding of cable of tethered UAVs comprises an encoder which reads the angle of cable feed; frequency converter regulating motor operation; a rotation sensor with a flag, which counts the drum revolutions; stepper motor driver, which reads the movement of the hawse on the ball-screw transmission and its position relative to the limit switches; computing module, which receives and processes incoming signals coming from an encoder, a frequency converter, a rotation sensor, a stepper motor driver, and based on the obtained information, correcting the operation of the system, correcting the cable tension; pulley located on metal frame and supply cable to UAV. System comprises a current collector which supplies power to a cable wound on a drum and supplied to the UAV without rotation of the supply wire of the external power supply during rotation of the drum.

EFFECT: providing smooth automated winding-unwinding of the cable and its correction during operation, preventing tangling, ensuring stable operation of the cable without movement of the supply wire when the drum moves.

6 cl, 5 dwg

Description

The invention relates to technological equipment for automatic winding and unwinding of a cable on a drum with further use of the cable for tethering unmanned aerial vehicles.

The analogue highlighted technical solution No. PCT/KR2019/016431 Ground station to support a tethered drone and a tethered drone system. Applicant Manmullab, South Korea. The ground station for supporting the tethered unmanned aerial vehicle and the tethered unmanned aerial vehicle system comprise: a power supply for supplying power to the tethered unmanned aerial vehicle through a cable; a tension control unit for adjusting the cable tension by winding or unwinding the cable; guide for guiding the cable to a given point; ground communication unit with a tethered drone via cable; and a control unit that controls the power unit to control the supply of power to the tethered unmanned aerial vehicle through the cable, and which controls the tension of the cable through the tension control unit, wherein the cable guide includes a guide shaft for guiding the cable to a predetermined height by the control unit by tension. Contains a tension control unit that can wind or unwind the cable from a reel and can be implemented in the form of a cylindrical rod that connects the tethered drone and the ground station.

The disadvantage is, despite the tension control unit, there is no cable tension sensor supplied to the UAV, which does not allow the cable to sag or jerk. The disadvantage is the immobility of the coil responsible for winding and unwinding the cable onto the drum, which is why there is a possibility of deviation from the declared layer-by-layer winding, as well as wear of the cable due to the constant change in the winding angle.

A known technical solution is RU 183808 U1 Device for winding and unwinding the tether cable of an unmanned aerial vehicle onto a drum. The device expands the arsenal of technical means used for winding and unwinding on a drum, by expanding their functionality and ensuring, during the process of unwinding and winding, the transmission of supply voltage through the cable-tether, as well as the transmission and receipt of information signals that are associated with the free length of the cable - tether (the lifting height of the unmanned aerial vehicle and the program for its use). A device for winding and unwinding a tether cable of an unmanned aerial vehicle onto a drum, together with the drum, contains a drive (motor and coupling) for rotating the drum axis, configured to attach to it a drum having parallel side stops, between which there is a cylindrical part designed for unwinding with it and winding the tether cable around it. It also contains a rotation drive for the axis of the cable-tether layer on the drum, installed parallel to the axis of the drum and made with the possibility of attaching the cable-tether layer to it in the form of a carriage, made with the possibility of bidirectional movement along the axis of the layer and uniform layer-by-layer supply of the cable-tether to the cylindrical part of the drum . The device has a contact ring mounted motionless on the drum axis; the output contacts of the power and signal wires are located on parallel side stops of the drum.

The disadvantage of the analogue is that it is powered through signal wires brought out to the outside of the side stop of the drum; accordingly, along with the rotation of the drum, the cores will also rotate, which exposes them to wear and entanglement. Another disadvantage is that the expansion of functionality stated in the technical result does not include the function of reading information about the operation of the device for its further automation.

The solution JSR-JZ-FE0206-200 is known and is available for purchase and is used for automated cable management for vehicles or other purposes. The device can control the speed and length of the retractable cable using a connected computer and appropriate commands. The cable reel can continuously transmit signals, current when rotating, and can automatically adjust the closed loop voltage when the cable unwinding speed is not the same. Provides dynamic feedback of rotation speed and other information to the host computer. The device has buttons for emergency shutdown and control, as well as a tension sensor.

The disadvantage of the device is the placement of the tension sensor, which is implicitly noted in the device - when located on the cable feed device, such a sensor does not have a sufficient range of information, since during takeoff and landing of the UAV, the cable can be positioned vertically and horizontally, due to which the adjustment of the drum rotation speed may be unnecessary pull the UAV, or, on the contrary, allow temporary sagging of the cable.

The prototype is a device with a pulley for supplying a power cable to a tethered unmanned aerial vehicle (RU 2791943). A device with a pulley for supplying a power cable to a tethered UAV contains a dosed load, a winch with a controller, a cable outlet fairlead, a belt and a converter. The electric drive shaft is connected by a belt to the pulley of the winch drum, which winds/unwinds the cable, which is fixed at the beginning on the drum. The cable goes around the grooves of the fixed and movable pulley rollers and passes through the hawse hole. The end of the cable passing through the fairlead hole is connected to a transducer located on the UAV frame, the axis of the moving roller is connected through a dosed load to the sensitive element of the sensor, which serves to determine the position of the moving roller and transmit information to the winch controller, the sensor body, the fairlead and the axis of the fixed roller are fixed to the winch frame . When the platform with the unmanned vehicle decreases, the drum continues to rotate, the movable roller rises to its maximum height due to the shortening of the cable branch, and the sensor commands the controller to enter the equilibrium mode. If the device rises higher due to drift, the cable is tensioned and the movable pulley roller, overcoming the mass of the dosed load, moves into the unwinding zone, and the controller commands the winch to unwind the cable with an increase in speed depending on the change in the amplitude of the deviation from the working height. If the device goes down due to drift, the cable is weakened, and the movable roller, under the influence of a dosed load, moves into the winding zone, and the controller commands the winch to wind the cable with increasing speed depending on the change in amplitude from the working height. The declared solution compensates for the jerky supply of the cable at the moment of its strong loosening/tension based on the buffer accumulation of the cable on the winch drum, compensating for the jerky feeding of the cable at the moment of its strong loosening/tension.

The disadvantage is the implementation of the pulley system and dosed load, which require a rigid vertical and horizontal base; in conditions of working with UAVs, implementing this solution will require additional design and its implementation in open space conditions for working with UAVs. The drum is powered through the slip ring connector and the ground power supply via a cable on the drum, which is a disadvantage because When the drum rotates, there is no guarantee of cable safety.

The technical result of the claimed invention is to ensure smooth supply of the cable to the UAV and its adjustment throughout the entire operation of the aircraft, to prevent entanglement and destabilization of the UAV due to cable tension, as well as to ensure stable operation of the cable, without movement of the supply wire when the drum moves .

The technical result is achieved by the fact that the system for automatic cable winding and unwinding of tethered UAVs contains:

- an encoder with which the cable feed angle is read and supplies this information to the computing unit;

- a frequency converter that regulates the operation of the motor depending on the information on the computing module;

- a rotation sensor with a flag that counts the drum revolutions and transmits the corresponding information to the computing module;

- a stepper motor driver that reads the movements of the fairlead on the ballscrew and its position relative to the limit switches, transmitting this information to the computing module;

- a computing module that receives and processes incoming signals coming from the encoder, frequency converter, rotation sensor, stepper motor driver, and, based on the information received, adjusts the operation of the system, adjusts the cable tension, thereby preventing destabilization of the UAV;

- a pulley located on a metal frame and supplying cable to the UAV;

- a current collector that provides power to the cable wound on the drum and supplied to the UAV without rotating the supply wire of the external power source when the drum moves.

The automatic cable winding and unwinding system for tethered UAVs contains elements that ensure automation and smooth cable unwinding and unwinding. In fig. Figure 1 shows a block diagram of the device, containing: a drum with side stops 1, a current collector 2, a rotation sensor with a flag 3, a motor with a gearbox 4, a pressure roller 5, a ball screw (ball screw) - 6, a fairlead 7, a stepper motor 8, a stepper motor driver 9, limit switches 10, frequency converter 11, computing module 12, metal structure for the pressure roller 13, springs for adjusting the metal structure 14, metal base 15, frame 16, encoder 17, pulley 18.

Figure 2 shows a sectional view of a drum with side limiters 1.

Figure 3 shows a drum 1 on a metal base 15 for winding and unwinding the cable; containing a stepper motor driver 9, a fairlead 7, a ball screw 6, limit switches 10, ensuring smooth winding and unwinding of the cable from and to the drum; metal structure for the pressure roller 13, springs for adjusting the metal structure 14, ensuring laying of the cable on the drum and motor with gearbox 4.

Figures 4 and 5 show a frame 16 for attaching a drum on a metal base 1 (15), a pulley 18, an encoder 17. The frame can be made with additional side walls 19, a rectangular structure 21, for further placement of a platform for UAV landing 20.

The system for automatic winding and unwinding of the cable for tethered UAVs contains: a metal base 15 (Fig. 3), on which a drum 375 mm wide with side limiters 1 (Fig. 2) is located (the width of the drum is due to the fact that the heat dissipation of the cable is 175 m, taking into account the efficiency will be about 800 W, which must be dissipated to avoid overheating, deformation and loss of cable performance); Parallel to the drum, on top, there is a pressure roller 5, on a metal structure 13 (Fig. 3), adjusted by springs 14 and ensuring layer-by-layer winding of the cable, without tangling or overlap; a rotation sensor with a flag 3, located next to the side stop of the drum, counting the revolutions and sending the corresponding information to the computing module 12; current collector 2 and motor with gearbox 4 (Fig. 3), providing power to the drum and the system as a whole; frequency converter 11, which, together with the computing module 12, changes the rotation frequency of the drum and cable winding and unwinding, respectively; Ball screw 6, the fairlead 7 moves between the limit switches 10 using a stepper motor 8, the fairlead moves according to the diameter of the cable and the revolutions of the drum using the stepper motor driver 9, which together ensures uniform supply of the cable from the drum to the encoder 17 (Fig. 5), and then to the UAV through pulley 18; a frame 16 on which a metal base with a drum 1, 15 is fixed on one side, and a pulley 18 on the opposite side, ensuring uniform supply of the cable to the UAV; in the middle of the frame there is an encoder 17 that controls the cable tension; computing module 12 receives incoming signals from the elements of the device, processes and corrects the operation of the motor with gearbox and drum 1, 4.

The invention works as follows: the automatic cable winding and unwinding system for tethered UAVs with an encoder winds up to 200 m of cable onto the drum cylinder 1 (Fig. 2), which then passes through the fairlead 7 (Fig. 3), encoder 17 (Fig. 5), pulley 18, connecting to the UAV and providing it with power, ensuring smooth adjustment of the cable length and stable operation of the UAV, respectively. The rotation of the drum 1 occurs using a motor with a gearbox 4 (Fig. 3); the frequency of the motor and the rotation of the drum coil are adjusted using a frequency converter 11 and a computing module 12. Above the drum 1 (Fig. 3), parallel to it, there is a roller clamp 5 on a metal structure 13, regulated by springs 14, ensuring layer-by-layer laying of the cable row to row; roller clamp 5 corresponds to the width of drum 1 and is located between its side stops. The cable is powered for further connection to the UAV using current collector 2; powered by wire from a ground power source (not shown in the figure); the wire transmits voltage; current collector 2 allows you to prevent the rotation of the supply wire together with drum 1. The cable wound on the drum reel passes through the fairlead 7 (Fig. 3), located parallel to the drum on the ball screw 6 and moving on it, according to the rotation of the drum, to the diameter of the cable, from the leftmost position, to the right extreme position (between limit switches 10, which also regulate the movement of the fairlead); the movement of the fairlead 7 is carried out using a stepper motor 8, the movement of the fairlead along the ball screw 6 is controlled using limit switches 10 and a stepper motor 8 in conjunction with the stepper motor driver 9, the rotation sensor flag 3 and the computing module 12 as follows: the fairlead 7 moves along the ball screw 6 using a stepper motor 8 interacting with the stepper motor driver 9; information from the limit switches 10 enters the driver 9, and, together with the information from flag 3, goes to the computing module 12, which adjusts and sets the operation of the stepper motor 8 and the movement of the fairlead 7, respectively. When drum 1 makes one revolution, the rotation sensor with flag 3 transmits information to the computing module 12, the computing module transmits information through the stepper motor driver 9 to the stepper motor 8 and the fairlead 7 moves along the ball screw 6 to the diameter of the cable. From the fairlead 7 (Fig. 3), the cable passes to the encoder 17 (Fig. 5), which controls the cable tension; a zero angle is set in the encoder, at which the device determines how to correct the position through feedback from the computing module 12 by transmitting signals: when the UAV takes off, the cable will be tensioned, and when landing or descending, it will be lowered, respectively, the encoder 17 reads the angle and adjusts the cable tension ensuring a smooth feeding, cable rewinding and stable operation of the UAV, respectively. From the encoder 17, the cable passes through the pulley 18 (Fig. 5), ensuring its smooth movement and further connection to the UAV. Computing module 12 is a programmable relay PR102-24.2416.06.2, which has 40 analog and discrete outputs; the module receives incoming information from the rotation sensor with flag 3, encoder 17, limit switches 10, stepper motor driver 9, frequency converter 11, processes and, based on the information received, adjusts the operation of the system: rotation speed of the drum 1, movement of the fairlead 7, cable tension.

Thus, automated winding and unwinding of the UAV cable is provided with a system against tangling and cable overlapping, as well as further smooth adjustment of the level of tension and cable supply for uninterrupted operation of the UAV and its unlimited hovering time in the air, as well as convenient take-off and landing and control.

Frame 16 (Fig. 4) can be made in the form of rails, or in the form of a metal base on which parts of the UAV cable winding and unwinding system are fixed. The frame can be made with additional side walls 19 (Fig. 4.5), for greater reliability and strengthening of the structure. The frame can be made with a rectangular structure above the pulley 21 (Fig. 5), for further placing on it a platform for landing the UAV 20.

A display can be connected to the system for convenient control and monitoring by the operator through the computing module.

Claims (6)

1. A system for automatic winding and unwinding of the cable of tethered UAVs, including a cylindrical drum with parallel side stops, designed for unwinding and winding of the tether cable, made with the possibility of fastening parallel to the axis of the drum of the cable layer with a fairlead, with the possibility of bidirectional movement of the axis of the layer and uniform layer-by-layer feeding tether cable to the drum, characterized in that the system is located on a frame on which a metal base with a drum is fixed on one side, and on the opposite side there is a pulley that ensures uniform supply of the cable to the UAV; in the middle of the frame there is an encoder that controls the cable tension; rotation sensor with a flag that counts the drum revolutions; also additionally contains a stepper motor driver that reads the movements of the fairlead on the ballscrew and its position relative to the limit switches; a current collector that provides power to the cable wound on a drum and supplied to the UAV; a computing module that receives and processes incoming signals coming from an encoder, frequency converter, rotation sensor, stepper motor driver, and, based on the received information, corrects the operation of the system. 2. The system according to claim 1, characterized in that the frame is made in the form of rails. 3. The system according to claim 1, characterized in that the frame is made in the form of a metal base. 4. The system according to claim 1, characterized in that the frame is made with additional lateral structural ribs. 5. The system according to claim 1, characterized in that the frame is designed to place the landing pad for the UAV above the pulley. 6. The system according to claim 1, characterized in that a display is connected to the computing module.