An unmanned aerial vehicle takeoff and landing system

Abstract

The present invention relates to the technical field of unmanned aerial vehicles, and discloses an unmanned aerial vehicle takeoff and landing system, which includes a takeoff and landing platform frame for supporting the unmanned aerial vehicle; a plurality of linear telescopic units arranged circumferentially along the takeoff and landing platform frame. The linear telescopic unit has a first end and a second end which are oppositely arranged and can be relatively fixed or moved. The first end of each linear telescopic unit is connected to the takeoff and landing platform frame through a first universal joint, and the second end of each linear telescopic unit can rotate relative to the takeoff and landing carrier through a second universal joint. By means of the cooperation of the linear telescopic unit, the first universal joint and the second universal joint, the present invention realizes the adjustment of six degrees of freedom of the takeoff and landing platform frame, avoids the influence on the takeoff and landing of the unmanned aerial vehicle caused by the movement of the takeoff and landing carrier and the unevenness of the takeoff and landing platform frame, provides a stable takeoff and landing environment for the unmanned aerial vehicle, not only realizes the safe and stable landing of the unmanned aerial vehicle at an unstable landing point, but also realizes the safe takeoff of the unmanned aerial vehicle in an unstable environment, and improves the success rate of the takeoff and landing of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and particularly to an unmanned aerial vehicle take-off and landing system. Background Art

[0002] Currently, the landing of unmanned aerial vehicles is mainly manually controlled, and manual control is prone to inevitable human errors, especially in some special scenarios such as bad weather, rough terrain, dynamic take-off and landing platforms, etc. For this reason, when a multi-rotor unmanned aerial vehicle lands, it is required that the terrain of the landing point is relatively stable and flat. The rough ground surface may cause the unmanned aerial vehicle to overturn during the landing process, resulting in certain economic losses and even personal injuries.

[0003] However, in actual application scenarios, there are many unstable take-off and landing platforms, such as vehicle-mounted take-off and landing platforms in motion, shipborne take-off and landing platforms at sea, etc. Unmanned aerial vehicles cannot safely and effectively take off and land on moving carriers, which limits the application scenarios and scope of unmanned aerial vehicles.

[0004] Compared with a stable take-off and landing platform, a mobile take-off and landing platform may have movements in three directions and rotations in three directions. Among them, the movements in three directions and the rotation around the vertical axis will interfere with the positioning of the unmanned aerial vehicle during landing; while the rotations in the other two directions will make it difficult for the take-off and landing platform to maintain a horizontal state, hindering the landing process of the unmanned aerial vehicle.

[0005] For this reason, a landing method for shipborne large unmanned aerial vehicles is provided in the prior art, which is specifically as follows: The unmanned aerial vehicle first follows the movement of the take-off and landing platform, hovers above the take-off and landing platform, continuously evaluates the state of the take-off and landing platform through the image feedback sent by the unmanned aerial vehicle, starts the landing program after confirming that the state of the take-off and landing platform is suitable for landing, otherwise waits and starts a new round of evaluation until successful landing. The advantage of this method is that the mechanical device is simple, but it has high requirements for the take-off and landing environment, slow response, and low success rate of take-off and landing.

[0006] Therefore, there is an urgent need to provide an unmanned aerial vehicle take-off and landing system for the take-off and landing of unmanned aerial vehicles in non-static scenarios. Summary of the Invention

[0007] The purpose of the present invention is to provide an unmanned aerial vehicle take-off and landing system capable of realizing the automatic landing of an unmanned aerial vehicle at an unstable landing point.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] An unmanned aerial vehicle take-off and landing system, comprising:

[0010] A take-off and landing platform frame for supporting the unmanned aerial vehicle;

[0011] A plurality of linear telescopic units are arranged circumferentially along the take-off and landing platform frame. The linear telescopic unit has a first end and a second end which are oppositely arranged and can be relatively fixed or moved. The first end of each linear telescopic unit is connected to the take-off and landing platform frame through a first universal joint, and the second end of each linear telescopic unit can rotate relative to the take-off and landing carrier through a second universal joint.

[0012] As a preferred technical solution of the above-mentioned unmanned aerial vehicle take-off and landing system, the take-off and landing platform frame includes:

[0013] A take-off and landing platform;

[0014] An upper connecting frame, one end of the upper connecting frame is connected to the take-off and landing platform, and the other end is connected to the first end of the corresponding linear telescopic unit through the first universal joint.

[0015] As a preferred technical solution of the above-mentioned unmanned aerial vehicle take-off and landing system, it further includes a clamping device for clamping the unmanned aerial vehicle placed on the take-off and landing platform. The clamping device includes:

[0016] Two first clamping rods arranged in parallel at intervals along the X direction, and the two first clamping rods can approach or move away from each other;

[0017] Two second clamping rods arranged in parallel at intervals along the Y direction, and the two second clamping rods can approach or move away from each other. The two first clamping rods and the two second clamping rods enclose an unmanned aerial vehicle placement area, and the X direction and the Y direction form an angle.

[0018] As a preferred technical solution of the above-mentioned unmanned aerial vehicle take-off and landing system, the clamping device further includes a rotation driving assembly, and the rotation driving assembly includes:

[0019] At least four pairs of guide wheels distributed circumferentially along the take-off and landing platform, and each guide wheel can rotate relative to the take-off and landing platform;

[0020] A transmission belt wound around each guide wheel, and both ends of the first clamping rod and both ends of the second clamping rod are connected to the transmission belt;

[0021] A rotation driving unit connected to one of the guide wheels to drive the guide wheel to rotate, so that the two first clamping rods approach each other and the two second clamping rods approach each other, or the two first clamping rods move away from each other and the two second clamping rods move away from each other.

[0022] As a preferred technical solution of the above-mentioned unmanned aerial vehicle take-off and landing system, the transmission belt meshes with the guide wheel for transmission.

[0023] As a preferred technical solution of the above unmanned aerial vehicle takeoff and landing system, the clamping device further includes:

[0024] A mounting bracket, the rotation driving assembly is connected to the mounting bracket;

[0025] A lifting driving assembly, one end of which is connected to the takeoff and landing platform, and the other end is connected to the mounting bracket, for driving the mounting bracket to lift relative to the takeoff and landing platform.

[0026] As a preferred technical solution of the above unmanned aerial vehicle takeoff and landing system, it further includes a lower connecting bracket for connecting the takeoff and landing carrier, and the second end of each linear telescopic unit is respectively connected to the lower connecting bracket through a second universal joint.

[0027] As a preferred technical solution of the above unmanned aerial vehicle takeoff and landing system, it further includes a shock absorber, one end of the shock absorber is connected to the lower connecting bracket, and the other end is used to connect the takeoff and landing carrier.

[0028] As a preferred technical solution of the above unmanned aerial vehicle takeoff and landing system, the linear telescopic unit is a cylinder, and the unmanned aerial vehicle takeoff and landing system further includes:

[0029] An air pump for supplying air to each cylinder;

[0030] A pneumatic switch valve, which corresponds to the cylinder one by one, and is used to connect one of the rodless cavity and the rod cavity of the cylinder to the air outlet of the air pump, and the other to the outside atmosphere, or to make the rodless cavity and the rod cavity of the cylinder not communicate with each other and not communicate with the air outlet of the air pump and the outside atmosphere.

[0031] As a preferred technical solution of the above unmanned aerial vehicle takeoff and landing system, it further includes:

[0032] A displacement sensor for measuring the extension amount of the piston rod of each cylinder;

[0033] An angle measurement unit for measuring the rotation angles of the takeoff and landing platform relative to the XY plane, YZ plane and XZ plane.

[0034] Advantages of the present invention: By cooperating the linear telescopic unit with the first universal joint and the second universal joint, the present invention can realize the adjustment of six degrees of freedom of the takeoff and landing platform, avoid the influence of the actions of the takeoff and landing carrier and the unevenness of the takeoff and landing platform on the takeoff and landing of the unmanned aerial vehicle, and provide a stable takeoff and landing environment for the unmanned aerial vehicle. It not only realizes the safe and stable landing of the unmanned aerial vehicle at an unstable landing point, but also realizes the safe takeoff of the unmanned aerial vehicle in an unstable environment, and improves the success rate of takeoff and landing of the unmanned aerial vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0036] Figure 1 is a schematic structural diagram of the UAV takeoff and landing system provided by the embodiment of the present invention;

[0037] Figure 2 is a schematic partial structural diagram of the UAV takeoff and landing system provided by the embodiment of the present invention;

[0038] Figure 3 is a schematic structural diagram of the landing platform provided by the embodiment of the present invention;

[0039] Figure 4 is a schematic partial structural diagram of the landing platform provided by the embodiment of the present invention.

[0040] In the figure:

[0041] 1. Landing platform; 11. Baffle; 2. Upper connecting frame; 3. Lower connecting frame; 4. First universal joint; 5. Second universal joint; 6. Shock absorber; 7. Pneumatic switch valve; 8. Clamping device; 81. First clamping rod; 82. Second clamping rod; 83. Guide wheel; 84. Transmission belt; 85. Slide block; 86. Mounting frame; 9. Lifting assembly; 100. Cylinder. Specific embodiments

[0042] To make the technical problems solved by the present invention, the technical solutions adopted, and the achieved technical effects clearer, the following will further illustrate the technical solutions of the present invention in combination with the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Additionally, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings rather than all of them.

[0043] Such as Figures 1 to 4As shown in the figure, this embodiment provides a drone takeoff and landing system, mainly for the takeoff and landing of multi-rotor drones. The drone takeoff and landing system includes a takeoff and landing platform frame and a plurality of linear telescopic units. Among them, the takeoff and landing platform frame is used to support the drone; the plurality of linear telescopic units are arranged circumferentially along the takeoff and landing platform frame. The linear telescopic unit has a first end and a second end that are oppositely arranged and can be relatively fixed or moved. The first end of each linear telescopic unit is connected to the takeoff and landing platform frame through a first universal joint 4, and the second end of each linear telescopic unit can rotate relative to the takeoff and landing carrier through a second universal joint 5. In this embodiment, the above linear telescopic unit is a cylinder 100, the first end is the piston rod of the cylinder 100, and the second end is the cylinder block of the cylinder 100. In other embodiments, the piston rod of the cylinder 100 can also be used as the second end, and the cylinder block of the cylinder 100 can be used as the first end; the above linear telescopic unit can also be an oil cylinder, an electric push rod or other structures that can realize linear telescopic motion.

[0044] In this embodiment, by cooperating the linear telescopic unit with the first universal joint 4 and the second universal joint 5, the adjustment of six degrees of freedom of the takeoff and landing platform frame can be realized, avoiding the influence of the actions of the takeoff and landing carrier and the unevenness of the takeoff and landing platform frame on the takeoff and landing of the drone, providing a stable takeoff and landing environment for the drone, not only realizing the safe and stable landing of the drone at an unstable landing point, but also realizing the safe takeoff of the drone in an unstable environment, and improving the success rate of the takeoff and landing of the drone.

[0045] The above takeoff and landing platform frame includes a takeoff and landing platform 1, an upper connecting frame 2 and a lower connecting frame 3. Among them, one end of the upper connecting frame 2 is connected to the takeoff and landing platform 1, and the other end is connected to the piston rod of the corresponding cylinder 100 through a first universal joint 4. The cylinder block of each cylinder 100 is respectively connected to the lower connecting frame 3 through a second universal joint 5.

[0046] The above takeoff and landing carrier is mainly a vehicle body or a hull, etc. In order to avoid the influence of the bumps of the vehicle body or the hull on the takeoff and landing of the drone, the drone takeoff and landing system provided in this embodiment further includes a shock absorber 6, and the lower connecting frame 3 is connected to the takeoff and landing carrier through the shock absorber 6. Preferably, the above shock absorber 6 is a wire rope shock absorber.

[0047] Furthermore, both the above upper connecting frame 2 and the lower connecting frame 3 are reticulated structures formed by welding a plurality of rods. Not only can the weight of the entire drone takeoff and landing system be reduced on the premise of ensuring strong load-bearing capacity, but also it is not easy to deform, and can play a good supporting role for the takeoff and landing platform 1. Preferably, both the upper connecting frame 2 and the lower connecting frame 3 are reticulated structures formed by welding section steels. Using section steels with a hollow structure can further reduce the weight of the drone takeoff and landing system.

[0048] In this embodiment, there are six cylinders 100. The upper connecting frame 2 includes an octagonal frame, a first connecting rod, and a second connecting rod. Among them, the octagonal frame includes four pairs of side beams that are opposite and parallel to each other, namely two first side beams, two second side beams, two third side beams, and two fourth side beams. The two ends of the first connecting rod are connected to the two first side beams and are parallel to the second side beam. The first connecting rod and each third side beam are connected by two second connecting rods. The piston rods of the six cylinders 100 are respectively connected to the two second side beams, two third side beams, and two fourth side beams through corresponding first universal joints 4.

[0049] The lower connecting frame 3 includes a hexagonal frame and three connecting beams. Among them, the hexagonal frame includes three pairs of side beams that are opposite and parallel to each other. Among them, the same ends of the three connecting beams meet and are connected, and the other ends are respectively connected to three side beams that are sequentially spaced apart. The six cylinders 100 are divided into three pairs, and each pair of cylinders 100 is arranged adjacent to each other. The cylinder bodies of each pair of cylinders 100 are respectively connected to the same side beam through corresponding second universal joints 5. The side beam connected with the second universal joint 5 is connected with a connecting beam. The two first universal joints 4 and two second universal joints 5 connected to the same pair of cylinders 100 are sequentially connected to enclose a trapezoid.

[0050] It should be noted that the structures of the upper connecting frame 2 and the lower connecting frame 3 are not limited to the above structures.

[0051] Furthermore, the above-mentioned UAV takeoff and landing system further includes a clamping device 8 for clamping the UAV placed on the takeoff and landing platform 1. The clamping device 8 includes two first clamping rods 81 and two second clamping rods 82 located above the takeoff and landing platform 1. Among them, the two first clamping rods 81 are arranged in parallel at intervals along the X direction, and the two first clamping rods 81 can approach or move away from each other; the two second clamping rods 82 are arranged in parallel at intervals along the Y direction, and the two second clamping rods 82 can approach or move away from each other; the X direction and the Y direction form an angle. Preferably, the X direction and the Y direction are perpendicular. In this embodiment, the cross-section of the takeoff and landing platform 1 is rectangular, the X direction is the length direction of the takeoff and landing platform 1, and the Y direction is the width direction of the takeoff and landing platform 1. In other embodiments, the cross-section of the takeoff and landing platform 1 can also be square, and the X direction and the Y direction are respectively the extending directions of two mutually perpendicular side walls of the takeoff and landing platform 1.

[0052] The two first clamping rods 81 and the two second clamping rods 82 enclose a UAV placement area. The UAV is placed on the takeoff and landing platform 1, and through the actions of the two first clamping rods 81 and the two second clamping rods 82, the UAV is clamped within the above-mentioned UAV placement area. By setting the clamping assembly, it is possible to prevent the UAV placed on the takeoff and landing platform 1 from jolting or being damaged due to the vibration or shaking of the takeoff and landing platform 1.

[0053] Further, the clamping device 8 further includes a mounting frame 86 and a rotation driving assembly. The rotation driving assembly includes a guide wheel 83, a transmission belt 84, and a rotation driving unit. Among them, the mounting frame 86 is a rectangular frame, located above the takeoff and landing platform 1. The four corners of the mounting frame 86 are arranged opposite to the four corners of the takeoff and landing platform 1; the guide wheel 83 is rotatably connected to the mounting frame 86, and there are four pairs of guide wheels 83, which are distributed along the circumferential direction of the mounting frame 86. Preferably, the four pairs of guide wheels 83 are respectively arranged at the four corners of the rectangular frame. In other embodiments, the number of pairs of guide wheels 83 is not limited to four, and can also be five pairs or more.

[0054] Each guide wheel 83 can rotate relative to the takeoff and landing platform 1; the transmission belt 84 is wound around each guide wheel 83, and both ends of the first clamping rod 81 and both ends of the second clamping rod 82 are connected to the transmission belt 84; the rotation driving unit is connected to one of the guide wheels 83 to drive the guide wheel 83 to rotate, so that the two first clamping rods 81 approach each other and the two second clamping rods 82 approach each other, or the two first clamping rods 81 move away from each other and the two second clamping rods 82 move away from each other. Preferably, the central axis of the guide wheel 83 is perpendicular to the takeoff and landing platform 1.

[0055] The above rotation driving unit includes a first motor. The first motor realizes the actions of the two first clamping rods 81 and the two second clamping rods 82 through a first transmission unit, reducing the cost of the UAV takeoff and landing system. The above first transmission unit is a bevel gear transmission structure to convert the rotation of the first motor around the horizontal axis into the rotation around the vertical axis.

[0056] Preferably, the first motor is a stepping motor to precisely control the rotation speed of the transmission. For the convenience of installation, in this embodiment, the output shaft direction of the first motor is perpendicular to the takeoff and landing platform 1, and the first motor is fixed to an outer side surface of the mounting frame 86 through a first connecting member. Preferably, the first connecting member is bolted to the motor mounting seat of the first motor, and the first connecting member is bolted to the mounting frame 86.

[0057] In this embodiment, the two guide wheels 83 of each pair of guide wheels 83 are respectively an inner wheel and an outer wheel. The four inner wheels enclose a rectangle, and the four outer wheels enclose a quadrilateral. The quadrilateral enclosed by the four outer wheels is sleeved outside the rectangle enclosed by the four inner wheels. The transmission belt 84 sequentially bypasses each guide wheel 83, so that the transmission belt 84 connecting any two adjacent outer wheels is parallel to the transmission belt 84 connecting the corresponding two inner wheels.

[0058] Among them, the drive belt 84 connecting two adjacent outer wheels is denoted as the outer belt, and the drive belt 84 connecting two adjacent inner wheels is denoted as the inner belt. The outer belts at both ends of the takeoff and landing platform 1 in the length direction are the first outer belt and the second outer belt respectively, the outer belts at both ends of the takeoff and landing platform 1 in the width direction are the third outer belt and the fourth outer belt respectively, the inner belt corresponding to the first outer belt is the first inner belt, the inner belt corresponding to the second outer belt is the second inner belt, the inner belt corresponding to the third outer belt is the third inner belt, and the inner belt corresponding to the fourth outer belt is the fourth inner belt.

[0059] One end of one first connecting rod is connected to the first outer belt, and the other end is connected to the second inner belt. One end of the other first connecting rod is connected to the second outer belt, and the other end is connected to the first inner belt. One end of one second connecting rod is connected to the third outer belt, and the other end is connected to the fourth inner belt. One end of the other second connecting rod is connected to the fourth outer belt, and the other end is connected to the third inner belt.

[0060] In order to improve the stability of the movement of the first clamping rod 81 and the second clamping rod 82 during the rotation of the drive belt 84, both ends of the first connecting rod are respectively connected to the drive belt 84 through a slider 85, both ends of the second connecting rod are respectively connected to the drive belt 84 through a slider 85, and each slider 85 is slidably connected to the mounting bracket 86. By slidably connecting the slider 85 to the mounting bracket 86, the movement of the first connecting rod and the second connecting rod is guided.

[0061] Furthermore, in order to prevent the two sliders 85 on the same side of the mounting bracket 86 from colliding, in this embodiment, elastic buffer blocks are provided on at least one of the opposite side surfaces of the two sliders 85 on the same side of the mounting bracket 86. Preferably, the elastic buffer blocks can be rubber parts or buffer structures composed of springs in the prior art, and will not be specifically limited here.

[0062] In other embodiments, elastic buffer blocks can also be provided in the middle of each slide rail so that there is at least a distance of one elastic buffer block between the two sliders 85 on the same side of the mounting bracket 86.

[0063] Furthermore, the drive belt 84 is in meshing transmission with the guide wheel 83. In this embodiment, the above drive belt 84 is a double-sided toothed synchronous belt, which avoids slipping between the guide wheel 83 and the drive belt 84, so as to ensure the clamping effect and synchronization rate of the first clamping rod 81 and the second clamping rod 82, and extend the service life of the drive belt 84.

[0064] Furthermore, the clamping device 8 further includes a lifting drive assembly. One end of the lifting drive assembly is connected to the takeoff and landing platform 1, and the other end is connected to the mounting bracket 86, and is used to drive the mounting bracket 86 to lift relative to the takeoff and landing platform 1. Due to the diversity of the UAV structure, only using the first clamping rod 81 and the second clamping rod 82 may not necessarily ensure the stability of the UAV placed on the takeoff and landing platform 1. By driving the mounting bracket 86 to lift through the lifting drive assembly, the first clamping rod 81 and the second clamping rod 82 can be used to clamp the UAV in the Z direction.

[0065] The above-mentioned lifting assembly 9 includes a plurality of lifting rods circumferentially distributed along the takeoff and landing platform 1 and lifting drive units corresponding to the lifting rods one by one. The lifting drive units are used to drive the lifting rods to lift. In this embodiment, there are four lifting rods, which are respectively arranged at the four corners of the takeoff and landing platform 1. The upper end of each lifting rod is connected to the mounting bracket 86 through a second connecting member. Preferably, the second connecting member is bolted to the lifting rod, and the second connecting member is bolted to the mounting bracket 86. In order to ensure the stability of the takeoff and landing platform 1 during the lifting process of the takeoff and landing platform 1, it is required that the four lifting drive units work synchronously.

[0066] The above-mentioned lifting drive unit can be a motor lead screw structure, or a motor worm and worm gear structure, or a motor rack and pinion structure, or a cylinder 100, or an oil cylinder, etc., which are not limited here.

[0067] In other embodiments, the above-mentioned lifting drive assembly may further include four lifting rods and a second motor. The second motor drives the four lifting rods to act synchronously through a second transmission unit. The above-mentioned second transmission unit can be a belt drive or a chain drive, etc., which are not introduced here.

[0068] Furthermore, a baffle 11 is respectively arranged on the four sides of the takeoff and landing platform 1. One end of the baffle 11 is connected to the takeoff and landing platform 1, and the other end protrudes from the takeoff and landing platform 1. The fixed end of the lifting drive assembly abuts against two adjacent baffles 11 and is connected to the two adjacent baffles 11. By providing the baffle 11, it is convenient for the installation of the lifting drive assembly without affecting the landing of the UAV.

[0069] Furthermore, the above-mentioned UAV takeoff and landing system further includes an air pump and a pneumatic switch valve 7. The air pump is used to supply air to each cylinder 100; the pneumatic switch valve 7 corresponds to the cylinder 100 one by one, and is used to selectively connect one of the rodless cavity and the rod cavity of the cylinder 100 to the air outlet of the air pump and the other to the outside atmosphere, or the rodless cavity and the rod cavity are not connected to each other and are both disconnected from the air outlet of the cylinder 100 and the outside atmosphere, or the rodless cavity and the rod cavity of the cylinder 100 are not connected to each other and are not connected to the air outlet of the air pump and the outside atmosphere.

[0070] The above-mentioned UAV lifting platform further includes a controller, a displacement sensor, and an angle measurement unit. Among them, the controller communicates with the pneumatic switch valve 7, the displacement sensor, and the angle measurement unit. The displacement sensor is used to measure the extension amount of the piston rod of each cylinder 100; the angle measurement unit is used to measure the rotation angles of the take-off and landing platform along the XY plane, YZ plane, and XZ plane.

[0071] The measurement signals of the displacement sensor and the angle measurement unit are sent to the controller. The controller determines the rotation angles of the take-off and landing platform 1 relative to the XY plane, YZ plane, and XZ plane according to the measurement signals of the angle measurement unit, calculates the telescopic amounts of the piston rods of each cylinder 100 when the take-off and landing platform 1 is converted from the current state to the horizontal state, calculates the difference in the telescopic amounts of the piston rods of each cylinder 100 according to the current telescopic amounts of the piston rods of each cylinder 100, and the controller controls the piston rods of each cylinder 100 to extend and retract by the corresponding difference in telescopic amounts, so that the take-off and landing platform 1 is in a stable horizontal state.

[0072] As for the adjustment of the telescopic amounts of each cylinder 100, the PID control algorithm can be adopted, and appropriate proportional, integral, and differential coefficients are selected to obtain better control performance.

[0073] When applying the above UAV take-off and landing system for the take-off and landing of the UAV, the angle measurement unit is used to measure the rotation angles of the take-off and landing platform along the XY plane, YZ plane, and XZ plane in real time. The controller controls the actions of the piston rods of each cylinder 100 according to the measurement results of the angle measurement unit, and measures the extension amounts of the piston rods of each cylinder 100 in real time through the displacement sensor, so that the take-off and landing platform 1 always maintains a horizontal state during the take-off and landing of the UAV, provides a stable take-off and landing environment for the UAV, and ensures the safety of the UAV during take-off and landing.

[0074] Perform a mechanical simulation on the upper connecting frame 2 of the above UAV take-off and landing system. Specifically, when the upper connecting frame 2 is in a stable state, it is mainly subjected to two external loads. One is the pressure of the take-off and landing platform 1 on the upper connecting frame 2, and the other is the supporting force of the cylinder 100 on the upper connecting frame 2 through the first universal joint 4; among them, a part of the pressure of the take-off and landing platform 1 on the upper connecting frame 2 comes from the gravity of the take-off and landing platform 1, and the other part comes from the pressure of the UAV staying on the take-off and landing platform 1 on the platform. Simplify the pressure of the take-off and landing platform 1 on the upper connecting frame 2 as a uniform load acting on the upper connecting frame 2, and simplify the connection of the cylinder 100 to the upper connecting frame 2 through the first universal joint 4 as a connection between a support plate with the same contact area and the upper connecting frame 2. The supporting force of the cylinder 100 on the upper connecting frame 2 through the first universal joint 4 is distributed on the support plate.

[0075] It should be noted that the support of the cylinder 100 on the upper connecting frame 2 through the first universal joint 4 cannot be simplified as a point, otherwise the stress will be infinite.

[0076] Through displacement simulation analysis, it is found that the displacement at the center of the upper connecting frame 2 is the largest, approximately 0.5 mm. Through strain and stress simulation, the maximum shear stress of the upper connecting frame 2 is about 2.4×105 N / m 2 , and by looking up the table, it can be known that the shear yield strength of the upper connecting frame 2 is about 1.5×108 N / m 2 , and the maximum shear force is much smaller than the shear yield strength of the material. Therefore, the upper connecting frame 2 is relatively reliable.

[0077] Perform mechanical simulation on the takeoff and landing platform 1 of the above-mentioned UAV takeoff and landing system. In order to more accurately represent the force exerted by the upper connecting frame 2 on the takeoff and landing platform 1, select to simulate the takeoff and landing platform frame including the upper connecting frame 2 and the takeoff and landing platform 1. When simulating the takeoff and landing platform frame, four external loads need to be considered. One is the pressure exerted by the lifting frames on the four corners of the takeoff and landing platform 1, designed to be 15 Kg; the second is the self-weight of the takeoff and landing platform 1; the third is the weight of the UAV; the fourth is the supporting force of the cylinder 100 on the upper connecting frame 2 through the first universal joint 4. In order to simplify the model, the weight of the UAV and the self-weight of the takeoff and landing platform 1 are used as distributed loads and evenly distributed on the takeoff and landing platform 1. Through simulation, it is found that the stress on the takeoff and landing platform 1 is much smaller than its yield strength; the maximum stress-bearing part of the upper connecting frame 2 is at the corners and the connection with the first universal joint 4, and the maximum stress obtained by simulation is still smaller than the shear yield strength of the material used. Therefore, the takeoff and landing platform frame is relatively reliable.

[0078] Perform mechanical simulation on the lower connecting frame 3 of the above-mentioned UAV takeoff and landing system. The lower connecting frame 3 is mainly subjected to two external loads. One is the supporting force of the shock absorber 6 on the lower connecting frame 3, and the second is the pressure of six cylinders 100 on the lower connecting frame 3 through the second universal joint 5. The same simplification method as when simulating the upper connecting frame 2 is adopted, and the connection surface between the shock absorber 6 and the lower connecting frame 3 is simplified to a fixed surface. Through displacement simulation, it can be obtained that the maximum total displacement of the lower connecting frame 3 is at the connection with the cylinder 100, approximately 0.6 mm; through strain and stress simulation, the maximum shear force can be obtained to be about 1.6×106 N / m 2 , which is much smaller than the shear yield strength of the material used, 1.5×108 N / m 2 , therefore, the structure of the lower connecting frame 3 is reliable.

[0079] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

[0080] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0081] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A drone takeoff and landing system, characterized in that, it includes: A takeoff and landing platform frame for supporting the drone; A plurality of linear telescopic units arranged circumferentially along the takeoff and landing platform frame. The linear telescopic unit has a first end and a second end that are oppositely arranged and can be relatively fixed or moved. The first end of each linear telescopic unit is connected to the takeoff and landing platform frame through a first universal joint (4), and the second end of each linear telescopic unit can rotate relative to the takeoff and landing carrier through a second universal joint (5); The takeoff and landing platform frame includes: A takeoff and landing platform (1); An upper connecting frame (2), one end of the upper connecting frame (2) is connected to the takeoff and landing platform (1), and the other end is connected to the first end of the corresponding linear telescopic unit through the first universal joint (4); The upper connecting frame (2) includes an octagonal frame. The octagonal frame includes four pairs of side beams that are opposite and parallel to each other. The side beams are two first side beams, two second side beams, two third side beams, and two fourth side beams. The linear telescopic units are respectively connected to two of the second side beams, two of the third side beams, and two of the fourth side beams through the corresponding first universal joints (4); It further includes a lower connecting frame (3) for connecting the takeoff and landing carrier. The second end of each linear telescopic unit is respectively connected to the lower connecting frame (3) through a second universal joint (5); Six linear telescopic units are provided; The lower connecting frame (3) includes a hexagonal frame and three connecting beams; the hexagonal frame includes three pairs of side beams that are opposite and parallel to each other; one ends of the three connecting beams meet and are connected, and the other ends are respectively connected to three side beams that are sequentially spaced apart; the six linear telescopic units are divided into three pairs, each pair of linear telescopic units is arranged adjacent to each other, and each pair of linear telescopic units is respectively connected to the same side beam through the corresponding second universal joint (5). The side beam connected with the second universal joint (5) is connected with a connecting beam; the two first universal joints (4) and the two second universal joints (5) connected to the same pair of linear telescopic units are sequentially connected to form a trapezoid.

2. The drone takeoff and landing system according to claim 1, characterized in that, it further includes a clamping device (8) for clamping the drone placed on the takeoff and landing platform (1). The clamping device (8) includes, above the takeoff and landing platform (1): Two first clamping rods (81) arranged parallel and spaced apart in the X direction. The two first clamping rods (81) can approach or move away from each other; Two second clamping rods (82) arranged parallel and spaced apart in the Y direction. The two second clamping rods (82) can approach or move away from each other. The two first clamping rods (81) and the two second clamping rods (82) enclose a drone placement area, and the X direction and the Y direction form an angle.

3. The drone takeoff and landing system according to claim 2, characterized in that, The clamping device (8) further includes a rotation driving assembly. The rotation driving assembly includes: At least four pairs of guide wheels (83) circumferentially distributed along the take-off and landing platform (1), each of the guide wheels (83) being capable of rotating relative to the take-off and landing platform (1); A transmission belt (84) wound around each of the guide wheels (83), with both ends of the first clamping rod (81) and both ends of the second clamping rod (82) connected to the transmission belt (84); A rotation driving unit connected to one of the guide wheels (83) to drive the guide wheel (83) to rotate, so that the two first clamping rods (81) approach each other and the two second clamping rods (82) approach each other, or the two first clamping rods (81) move away from each other and the two second clamping rods (82) move away from each other.

4. The UAV take-off and landing system according to claim 3, wherein, The transmission belt (84) meshes with the guide wheel (83) for transmission.

5. The UAV take-off and landing system according to claim 3, wherein, The clamping device (8) further includes: A mounting frame (86), to which the rotation driving assembly is connected; A lifting driving assembly, one end of which is connected to the take-off and landing platform (1) and the other end is connected to the mounting frame (86), for driving the mounting frame (86) to lift relative to the take-off and landing platform (1).

6. The UAV take-off and landing system according to claim 1, wherein, It further includes a shock absorber (6), one end of the shock absorber (6) being connected to the lower connecting frame (3) and the other end being used to connect to the take-off and landing carrier.

7. The UAV take-off and landing system according to any one of claims 1 to 5, wherein, The linear telescoping unit is a cylinder (100), and the UAV take-off and landing system further includes: An air pump for supplying air to each cylinder (100); A pneumatic switch valve (7), corresponding to each cylinder (100) one by one, for connecting one of the rodless chamber and the rod chamber of the cylinder (100) to the air outlet of the air pump and the other to the outside atmosphere, or for disconnecting the rodless chamber and the rod chamber of the cylinder (100) from each other and from the air outlet of the air pump and the outside atmosphere.

8. The UAV take-off and landing system according to claim 7, wherein, It further includes: A displacement sensor for measuring the extension amount of the piston rod of each cylinder (100); An angle measuring unit for measuring the rotation angles of the take-off and landing platform relative to the XY plane, the YZ plane, and the XZ plane.

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