Unmanned aerial vehicle net collision recovery device

Abstract

The invention discloses an unmanned aerial vehicle net collision recovery device, and belongs to the technical field of unmanned aerial vehicles. The unmanned aerial vehicle net collision recovery device comprises four damping mechanisms arranged on a base, each damping mechanism comprises a wire spool rotationally installed on the base and a damper fixedly installed on the base and connected with the wire spool through a coupler, a damping rope is wound around the wire spool, the free end of the damping rope is connected with a recovery net, and the free end of the damping rope is connected with the recovery net. When the unmanned aerial vehicle collides with the recovery net, the recovery net is impacted to move towards the side opposite to the coming direction of the unmanned aerial vehicle, and the damper is pulled to rotate through the damping rope. Through the adjustable damping mechanism, reliable recovery of unmanned aerial vehicle collision nets with different kinetic energy and different pitching angles can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicles, and in particular relates to a net-collision recovery device for unmanned aerial vehicles. Background Art

[0002] Currently, unmanned aerial vehicles have advantages such as low cost, high adaptability, strong flexibility, and diverse onboard equipment. As the application scenarios of unmanned aerial vehicles gradually increase, the number of precision instruments and equipment carried on them also continues to increase. Therefore, the reliability of the unmanned aerial vehicle recovery method plays an important role in its cost maintenance and lifespan.

[0003] Conventional unmanned aerial vehicle recovery methods include runway recovery, skyhook recovery, parachute recovery, and net-collision recovery, etc. Among them, net-collision recovery has advantages such as high efficiency, strong portability, and small damage to the airframe. Chinese patent document CN105438494A discloses a net-collision recovery device for an unmanned aerial vehicle with retractable buffering, including a support structure and a net surface. A sliding device or a slide rail device is arranged at the bottom of the support mechanism, and through connecting a damper, the net surface can achieve retractable buffering of the whole device after catching the unmanned aerial vehicle. In this device, at the moment when the unmanned aerial vehicle touches the net, since most of the kinetic energy is borne by the net ropes connected to the vertical poles, a high strength requirement is imposed on the recovery net. At the same time, after recovery, the unmanned aerial vehicle freely lands, there is a risk of secondary damage to the airframe. Chinese patent document CN217969958U discloses a recovery net device for an unmanned aerial vehicle, including a net surface, a fixed rod unit, as well as springs and elastic connectors. When the unmanned aerial vehicle hits the recovery net, most of the kinetic energy is absorbed by the springs and converted into elastic potential energy, and when the elastic potential energy exceeds the bearing limit of the springs, the springs consume the elastic potential energy until they break, and the remaining kinetic energy is absorbed by the elastic connectors, so that the recovery net wraps the unmanned aerial vehicle. Since the springs break during the recovery operation, this device is difficult to reuse. At the same time, for airframes with different kinetic energies, different springs and elastic connectors need to be matched, the applicable range is limited, and there are certain safety hazards. Summary of the Invention

[0004] The purpose of the present invention is to provide a net-collision recovery device for an unmanned aerial vehicle, which can achieve the recovery of airframes with different models and different kinetic energies within a certain range and improve the reusable rate.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] An unmanned aerial vehicle (UAV) net-collision recovery device includes a base and a collision net installed on the base. The collision net includes two rods installed on the base and a recovery net arranged between the two rods. It also includes four damping mechanisms arranged on the base. Each damping mechanism includes a wire winding disc rotatably installed on the base and a damper fixedly installed on the base and connected to the wire winding disc through a coupling. A damping rope is wound around the wire winding disc. Wherein, rope wheels are respectively arranged at the upper and lower ends of the two rods. The free ends of the damping ropes of the two damping mechanisms respectively bypass the corresponding rope wheels on one rod to be correspondingly connected to two corners on one side of the recovery net, and the free ends of the damping ropes of the other two damping mechanisms respectively bypass the corresponding rope wheels on the other rod to be correspondingly connected to two corresponding corners on the other side of the recovery net, so as to connect the recovery net between the two rods. When the UAV impacts the recovery net, the recovery net is impacted and moves to the side opposite to the coming direction of the UAV, and drives the damper to rotate by pulling the damping rope.

[0007] In other embodiments, the lower ends of the two rods are respectively connected to the base through rotating shafts, and a locking device for applying a locking force to the rotating shafts is further included. When the locking device is in the released state, the collision net can rotate along the coming direction of the UAV through the rotating shaft. When the locking device is in the locked state, the rotation of the collision net along the coming direction of the UAV through the rotating shaft is restricted.

[0008] In other embodiments, the locking device includes a damping block in frictional contact with the rotating shaft and a locking mechanism for applying pressure to the damping block.

[0009] In other embodiments, the locking mechanism includes an adjusting structure to adjust the magnitude of the frictional force applied by the damping block to the rotating shaft by changing the magnitude of the pressure applied to the damping block, so that the locking device is in a released state or multiple locking states with different locking forces.

[0010] In other embodiments, the magnitude of the frictional force applied to the rotating shaft is adapted to the magnitude of the impact force generated when the UAV impacts the recovery net, so as to overcome the frictional force through the impact force to release the locked state when the UAV impacts the recovery net.

[0011] In other embodiments, the damping blocks are hard rubber blocks symmetrically arranged on both sides of the rotating shaft. The locking mechanism includes a push rod and a turning handle. The push rod abuts against the damping block, and the push rod can be screwed in and out by rotating the turning handle to change the magnitude of the pressure applied to the damping block.

[0012] In other embodiments, when the UAV does not impact the recovery net, the collision net inclines at a predetermined angle in the coming direction of the UAV. When the UAV net-collision recovery is completed, the collision net inclines at a predetermined angle in the direction opposite to the coming direction of the UAV.

[0013] In other embodiments, the inclination angle corresponds to multiple locking states with different locking forces.

[0014] In other embodiments, the base further includes cushioning material for supporting the two rods when the drone is recovered by hitting the net.

[0015] In other embodiments, the damper is a power-adjustable damper, and the base is further provided with a controller connected to the power-adjustable damper.

[0016] By designing the damping of the locking device and the power of the damper to be adjustable, the present invention realizes the dynamic adjustment of drones with different kinetic energies during the process of hitting the net. At the same time, due to having two working forms of lodging and fixing, by adjusting the initial fixing angle of hitting the net, reliable recovery of drones with different kinetic energies and different pitching angles when hitting the net can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the initial state of the drone net-hitting recovery device according to an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the first bench structure of the base;

[0019] Figure 3 Schematic diagram of the second bench structure of the base;

[0020] Figure 4 Schematic diagram of the third bench structure of the base;

[0021] Figure 5 Schematic diagram of the net-hitting rod group structure;

[0022] Figure 6 Schematic diagram of the locking mechanism structure;

[0023] Figure 7 Schematic diagram of the lodging state of the drone net-hitting recovery device after the recovery is completed. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Hereinafter, the technical solutions of the present invention will be described in detail with reference to the accompanying drawings.

[0025] Existing drone net-hitting recovery devices usually adopt methods such as overall device buffering or elastic member energy absorption to linearly and non-linearly consume the kinetic energy of the net-hitting drone. On the one hand, the above devices require a good test site environment and a relatively suitable recovery net. For different types and models of aircraft, the preliminary debugging work is relatively cumbersome, and the protection of the vertical dropping process of the aircraft body is not carried out. On the other hand, the secondary utilization rate of the device is not high, and it is often necessary to frequently debug and replace its buffer components, increasing the use cost and there is a certain risk of component failure.

[0026] From the perspective of the practicality of the UAV net-collision recovery device, this invention takes the requirements for environmental adaptability during the device construction process, the reusable rate of the device, the damage degree of the device to the airframe itself during the recovery process, and the reliability and adjustability of the device itself as improvement goals, and proposes a UAV net-collision recovery device. This device includes a base, a net installed on the base, and four damping mechanisms arranged on the base.

[0027] Each damping mechanism includes a wire reel rotatably installed on the base, a damper fixedly installed on the base and connected to the wire reel through a coupling, and a damping rope wound around the wire reel.

[0028] Rope wheels are respectively arranged at the upper and lower ends of the two rods. The free ends of the damping ropes of the two damping mechanisms respectively bypass the corresponding rope wheels on one rod to be correspondingly connected to the two corners on one side of the recovery net, and the free ends of the damping ropes of the other two damping mechanisms respectively bypass the corresponding rope wheels on the other rod to be correspondingly connected to the two corresponding corners on the other side of the recovery net, so as to connect the recovery net between the two rods.

[0029] When the UAV impacts the recovery net, the recovery net is impacted and moves to the side opposite to the direction of the UAV, and rotates the damper by pulling the damping rope.

[0030] Refer to Figures 1-4 , the base of this device includes a first bench 1, a second bench 2, and a third bench 3.

[0031] The first bench 1 is welded by profiles (such as 4mm thick stainless steel square tubes). A wire reel mounting hole 1.1 is opened on the higher side of the top, and is connected to the wire reel bearing seat 9 and the wire reel 8 through bolts; a damper mounting hole 1.3 is opened on the lower side of the top, and is connected to the damper shock absorber block 7 and the damper 6 through bolts; an installation hole 1.2 is left on the right side and is connected to the second bench 2 through bolts; an installation position 1.4 is left on the left side for clamping the controller 5; a ground nail mounting hole 1.5 is opened at the bottom, and the first bench 1 is fixedly connected to the ground through ground nails or anchor bolts.

[0032] The second bench 2 is welded by profiles (such as 4mm thick stainless steel square tubes). An installation hole 2.1 is left on the top for bolt connection with the fixing block in the alternative plan; an installation hole 2.2 is opened on one side for bolt connection with the damping block 14; an installation hole 2.3 is opened on the other side, and a nut is welded outside the hole position, and the push rod part of the locking device 13 can pass through this hole; an installation hole 2.4 is left at the bottom of the side and is connected to the first bench 1 through bolts; an installation hole 2.5 is left at the top of the middle section for connecting the rod group bearing seat 11 and its supporting shock absorber block 12.

[0033] The third mount 3 is formed by connecting profiles (such as 4-mm-thick stainless steel square pipes) and pipe fittings, and consists of a top cover 3.1, shock-absorbing cotton 3.2, support feet 3.3, and a base 3.4. During the process of net impact recovery and the initial setup of the device, it mainly plays a role in buffering and supporting the rod group 4, and can also be connected to the connecting rope of the ground protection net to achieve ground protection for the aircraft body.

[0034] Exemplarily, folding casters are provided at the bottom of the above mount to facilitate the movement of the recovery device.

[0035] Refer to Figure 5 , each rod of the impact net is composed of the rod group 4. Exemplarily, it is formed by bolt-connecting one upper carbon rod 4.1, two middle carbon rods 4.2, and one lower carbon rod 4.3 through a carbon tube joint 4.6. The carbon tube joint 4.6 has threaded holes; an upper rope wheel bracket 4.4 is installed at the top of the upper carbon rod 4.1 for fixing the rope wheel (fixed pulley), and the rope wheel is connected to a damping rope (such as a nylon rope) 17. A guiding ring 4.5 is installed in the middle for restricting the moving direction of the damping rope 17. There are holes in the middle section of the middle carbon rod 4.2 for cooperating with the guiding ring 4.5, and the guiding ring 4.5 has threaded holes. The middle part of the lower carbon rod 4.3 is connected to a lower rope wheel bracket 4.7 to fix the rope wheel and connect it to the damping rope, and there is a through hole at the bottom for bolt connection with the carbon rod rotating shaft 4.8. The carbon rod rotating shaft 4.8 can be connected to the corresponding position of the second mount 2 through the rod group bearing seat 11.

[0036] The carbon rod is a 5-mm-thick carbon fiber tube to reduce the self-weight of the rod group. To increase the radial strength of the carbon fiber tube, the fiber laying direction is 0°, ±45°, 90°.

[0037] The recovery net is formed by weaving a polyester net, with a size of not less than 5m * 5m. The horizontal spacing of the grid is less than the vertical spacing to reduce the damage to the nose position during the net impact process. Connecting ropes are provided around the recovery net and fastened to the damping ropes, and are connected to the damper and the winding disc through rope wheels.

[0038] Exemplarily, the polyester net connecting rope is connected to the damping rope through a tensiometer to detect the impact force received by the recovery net when the UAV is recovered.

[0039] In the present invention, a locking device for applying a locking force to the rotating shaft is further included. When the locking device is in the released state, the impact net can rotate along the direction of the UAV coming through the rotating shaft; when the locking device is in the locked state, the rotation of the impact net along the direction of the UAV coming through the rotating shaft is restricted. Exemplarily, the locking device includes a damping block in frictional contact with the rotating shaft and a locking mechanism for applying pressure to the damping block.

[0040] As Figure 6As shown, the main body of the locking mechanism 13 consists of a push rod 13.1 and a rotary handle 13.2. The push rod 13.1 abuts against the damping block 14 (for example, interference fit). The damping block 14 is a hard rubber block and is symmetrically arranged on both sides of the rotating shaft. The push rod 13.1 is threaded and can cooperate with the welding nut outside the mounting hole 2.3 of the second bench. Rotating the rotary handle 13.2 can screw the push rod 13.1 in and out, and apply pressure to the damping blocks 14 arranged at both ends through the push rod 13.1. The locking and releasing functions of the corresponding position of the carbon rod rotating shaft 4.8 in the rod group 4 can be completed by the frictional force generated by the rubber block. The number of turns of the rotary handle 13.2 can determine the magnitude of the damping force generated by the damping block 14 on the rod group 4, so as to adjust the magnitude of the frictional force applied by the damping block on the rotating shaft by changing the magnitude of the pressure applied to the damping block, so that the locking device is in multiple locking states of the releasing device or different locking forces.

[0041] In the present invention, the magnitude of the frictional force applied to the rotating shaft is adapted to the magnitude of the impact force generated when the unmanned aerial vehicle hits the recovery net, so as to overcome the frictional force by the impact force to release the locked state when the unmanned aerial vehicle hits the recovery net. Exemplarily, a dial is provided at the locking device to facilitate displaying the applied damping magnitude.

[0042] In other embodiments, when the unmanned aerial vehicle does not hit the recovery net, the hitting net is inclined by a predetermined angle in the direction of the oncoming direction of the unmanned aerial vehicle, such as Figure 1 the state shown. When the recovery of the unmanned aerial vehicle by hitting the net is completed, the hitting net is inclined by a predetermined angle in the direction opposite to the oncoming direction of the unmanned aerial vehicle. When the weight and / or speed of the recovered unmanned aerial vehicle is too large, when the recovery of the unmanned aerial vehicle by hitting the net is completed, the hitting net is inclined in the direction opposite to the oncoming direction of the unmanned aerial vehicle until it is substantially in a horizontal state (lodging state), as Figure 7 shown, which can reduce the impact damage to the rod group 4 generated when the unmanned aerial vehicle hits the net, and contribute to the realization of overload protection for the unmanned aerial vehicle body.

[0043] Exemplarily, an air cushion is placed between the second bench and the third bench to offset the risk of secondary damage generated when the unmanned aerial vehicle freely falls to the ground.

[0044] During use, the rod group is horizontally placed on the third bench 3 before assembly. The damping rope 17 passes through the rod group guide ring 4.5 and the rope wheel brackets 4.4 and 4.7, and then one end is connected to the recovery net. After being erected at the second bench by a hydraulic cylinder or other tools, the other end is wound around the winding disc 8. The winding disc shaft is connected to the damper 6 through a coupling. Since the damping of the damper 6 can be adjusted after startup, the damping force can be adjusted to balance the dead weight of the recovery net.

[0045] The initial state of the recovery net is located on the left side of the rod group, that is, on the side opposite to the direction of the oncoming UAV hitting the net, and has a certain inclination angle. At the same time, by adjusting the fixed angle of the rod group 4 on the second rack, the device can achieve differential adjustment for aircraft with different net-hitting angles, and can avoid the overturning phenomenon caused by the UAV hitting the net at too high a height.

[0046] When the UAV hits the recovery net, the recovery net will move to the right due to the impact and pull the damping rope 17. At the same time, the damping rope 17 pulls the damper 6 to rotate, which can convert the kinetic energy generated during the net-hitting process into the internal energy of the damper, completing the required kinetic energy cancellation.

[0047] By setting the power of the damper 6 through the controller, the net-hitting recovery of aircraft with different kinetic energies can be achieved.

[0048] When the UAV has too much kinetic energy, in order to make full use of the energy conversion effect of the damper, the rod group 4 can be laid down. Through the downward guiding effect on the net generated, the UAV and the recovery net can move forward more. The laying-down action of the rod group 4 can reduce the impact damage to the rod group 4 when the UAV hits the net, and contribute to the overload protection of the UAV body; among them, by adjusting the number of rotation turns of the locking mechanism 13, the laying-down degree of the rod group 4 can be modified, and through the friction between the rubber block and the rod group, part of the kinetic energy of the UAV can be absorbed and converted.

[0049] The present invention can complete the flexible construction of the device in a limited space and has a high reuse rate. The device has good protection for the airframe. By using ground protection measures such as air cushions and ground nets, as well as customized flat nets and damping ropes, etc., the impact damage to the airframe itself during the recovery process is fully reduced.

[0050] The present invention uses high-strength carbon fiber tubes as the main body structure of the rod group, which not only reduces the weight of the device but also improves the strength of the device; uses stainless steel square tubes to weld the rack, and through reasonable collocation of ground nails, the overall reliability and stability of the device are enhanced.

[0051] The present invention has two operating modes: a fixed rod group and a laid-down rod group. And relying on the adjustability of the locking device and the damper, it can be dynamically adjusted for aircraft with different kinetic energies, with good adaptability and expandability. By carrying a tensiometer sensor, the parametric analysis of the net-hitting recovery process can be completed.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An unmanned aerial vehicle net-collision recovery device, comprising a base and a net for collision installed on the base, the net for collision including two rods installed on the base and a recovery net arranged between the two rods, characterized in that, It further includes four damping mechanisms arranged on the base. Each damping mechanism includes a wire winding disc rotatably mounted on the base, a damper fixedly mounted on the base and connected to the wire winding disc through a coupling, and a damping rope wound around the wire winding disc. Wherein, rope wheels are respectively arranged at the upper and lower ends of the two rods, and the free ends of the damping ropes of the two damping mechanisms respectively bypass the corresponding rope wheels on one rod to be correspondingly connected to two corners on one side of the recovery net, and the free ends of the damping ropes of the other two damping mechanisms respectively bypass the corresponding rope wheels on the other rod to be correspondingly connected to two corresponding corners on the other side of the recovery net, so as to connect the recovery net between the two rods. When the drone hits the recovery net, the recovery net moves to the side opposite to the direction of the drone due to the impact, and pulls the damper to rotate through the damping rope.

2. The drone net-collision recovery device according to claim 1, characterized in that, The lower ends of the two rods are respectively connected to the base through rotating shafts, and it further includes a locking device for applying a locking force to the rotating shafts. When the locking device is in the released state, the net-hitting device can rotate along the direction of the drone through the rotating shaft. When the locking device is in the locked state, the rotation of the net-hitting device along the direction of the drone through the rotating shaft is restricted.

3. The drone netting recovery device according to claim 2, wherein, The locking device includes a damping block in frictional contact with the rotating shaft and a locking mechanism for applying pressure to the damping block.

4. The drone net-collision recovery device according to claim 3, wherein, The locking mechanism includes an adjusting structure to adjust the magnitude of the frictional force applied by the damping block to the rotating shaft by changing the magnitude of the pressure applied to the damping block, so that the locking device is in the released state or multiple locking states with different locking forces.

5. The drone net-collision recovery device according to claim 3, wherein, The magnitude of the frictional force applied to the rotating shaft is adapted to the magnitude of the impact force generated when the drone hits the recovery net, so as to overcome the frictional force through the impact force to release the locked state when the drone hits the recovery net.

6. The drone netting recovery device according to claim 3, wherein, The damping block is a hard rubber block symmetrically arranged on both sides of the rotating shaft. The locking mechanism includes a push rod and a turning handle. The push rod abuts against the damping block, and the push rod can be screwed in and out by turning the turning handle to change the magnitude of the pressure applied to the damping block.

7. The drone net-collision recovery device according to claim 4, characterized in that, When the drone does not hit the recovery net, the net-hitting device inclines at a predetermined angle in the direction of the drone. When the recovery of the drone by hitting the net is completed, the net-hitting device inclines at a predetermined angle in the direction opposite to the drone.

8. The drone net-collision recovery device according to claim 4, characterized in that, The inclination angle corresponds to multiple locking states with different locking forces.

9. The drone net-collision recovery device according to claim 7, wherein, The base further includes a buffer material for supporting the two rods when the recovery of the drone by hitting the net is completed.

10. The drone net-collision recovery device according to claim 1, wherein The damper is a power-adjustable damper, and the base is further provided with a controller connected to the power-adjustable damper.

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