Self-balancing undercarriage system of vertical take-off and landing aircraft and landing control method of self-balancing undercarriage system

Abstract

The invention discloses a vertical take-off and landing aircraft self-balancing undercarriage system and a landing control method thereof, and belongs to the technical field of vertical take-off and landing aircraft undercarriages. The self-balancing undercarriage system comprises an undercarriage, a control system and a direct-current power source, the undercarriage is composed of an undercarriage supporting arm and four air cylinder supporting feet, and the four air cylinder supporting feet are installed at the four supporting arm ends of the undercarriage supporting arm. A concealed low-pressure cavity and a concealed high-pressure cavity are designed in the undercarriage supporting arm and are connected with the air cylinder through one-way valves respectively. A distance sensor is installed in the center of the undercarriage supporting arm. And when the robot lands on the uneven ground, the four air cylinder supporting legs can adapt to the ground condition. By combining the self-balancing undercarriage system with the control method, balanced landing of the vertical take-off and landing aircraft on the uneven ground can be achieved, the adaptability to the ground is enhanced, the requirement of the vertical take-off and landing aircraft for a landing site is lowered, and meanwhile impact-free landing is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of landing gears for vertical takeoff and landing aircraft, and particularly to a self-balancing landing gear system for vertical takeoff and landing aircraft and a landing control method therefor. Background Art

[0002] As an emerging industry, the low-altitude economy has the characteristics of a long industrial chain, high technological content, and strong innovation ability, promoting the economic development of various countries. The low-altitude economy is driven by various low-altitude flight activities of manned and unmanned aircraft, driving the integrated development of related fields. Vertical takeoff and landing aircraft are one of the important carriers of the low-altitude economy, with characteristics such as vertical takeoff and landing capabilities, intelligence, and systematization, and are widely used in military and civilian fields. In the military field, vertical takeoff and landing aircraft can be equipped with various advanced devices to perform functions such as reconnaissance, search and rescue, and transportation. In the civilian field, vertical takeoff and landing aircraft can be used for short-distance transportation, power line inspection, environmental and geographical mapping, and other aspects.

[0003] With the improvement of the modernization and complexity of missions, in complex and changing environments, there is usually a lack of flat takeoff and landing sites, and the ground conditions are complex. Vertical takeoff and landing aircraft face the problem of landing on complex ground. Traditional landing gears mainly use skid-type and bionic multi-legged types. Skid-type landing gears require specific takeoff and landing sites and cannot adapt to different uneven ground environments. The landing gear does not have the ability to adapt to the ground. When landing on uneven ground, there may be a risk of tipping over during landing. Therefore, a landing gear system with intelligence and adaptability to complex environments is crucial for the rapid response and efficient execution of vertical takeoff and landing aircraft. Patent CN221820292U discloses a four-legged balanced landing gear for unmanned aircraft. Four leg assemblies are driven by a first servo motor to independently swing back and forth around the Z-axis to achieve forward and backward movement. The support legs are driven by a second servo motor to independently swing around the hinge points with the second arm and / or the third arm to achieve left and right movement. When the unmanned aircraft lands, the four leg assemblies can independently extend or retract to adapt to the ground at different heights or inclinations.

[0004] Bionic multi-legged landing gears are generally used in conjunction with laser range sensors. When preparing to land, the aircraft hovers in the air near the ground. First, the laser range sensor is used to detect the distance between each support leg and the ground. Then, by adjusting the length of each support leg, it can be made to match the undulations of the ground. Then, the aircraft is slowly brought closer to the ground until it lands smoothly on the ground. However, at the moment when the aircraft touches the ground, the descent speed of the aircraft suddenly drops to zero, and the landing gear will be subjected to a large impact force, affecting the service life of the landing gear and the aircraft.

[0005] In summary, it is necessary to provide a self - balancing landing gear system and control method for a vertical take - off and landing aircraft with high environmental adaptability to ensure that the fuselage of the vertical take - off and landing aircraft remains balanced when landing on uneven ground, achieve shock - free landing, and ensure the safety and comfort of the landing process of the vertical take - off and landing aircraft. Summary of the Invention

[0006] To solve or partially solve the problems existing in the related technologies, the present invention provides a self - balancing landing gear system for a vertical take - off and landing aircraft and its landing control method, which can control the cylinders of the landing gear system according to the flight height of the vertical take - off and landing aircraft to achieve adaptation to complex ground and shock - free landing.

[0007] The above - mentioned self - balancing landing gear system for a vertical take - off and landing aircraft includes a landing gear, a control system, and a DC power supply. The DC power supply is used to provide energy for the landing gear and the control system.

[0008] The landing gear includes a support arm 1, four support leg cylinders 2, an air pump 3, a three - position four - way electromagnetic directional control valve 4, a low - pressure check valve 5, and a two - position two - way electromagnetic directional control valve 6.

[0009] The four support leg cylinders 2 are respectively installed at the ends of the support arm 1. A hidden low - pressure chamber 7 and a high - pressure chamber 14 are provided inside the support arm 1.

[0010] The air pump 3 is arranged on the support arm 1. The output end of the air pump 3 is connected to the port P of the three - position four - way electromagnetic directional control valve 4 through a pipeline. An overflow valve 10 is also provided on the connecting pipeline between the air pump 3 and the three - position four - way electromagnetic directional control valve 4. The port B of the three - position four - way electromagnetic directional control valve 4 is connected to the low - pressure chamber 7 through a pipeline. A throttle valve 11 is provided on the connecting pipeline between the three - position four - way electromagnetic directional control valve 4 and the low - pressure chamber 7. The rodless end air inlet of any one of the support leg cylinders 2 is connected to the low - pressure chamber 7 through an intake pipe, and a low - pressure check valve 5 is provided on the intake pipe. The low - pressure check valve 5 allows gas to flow from the low - pressure chamber 7 to the support leg cylinder 2.

[0011] The rod - end air inlet of any one of the support leg cylinders 2 is connected to the port A of the three - position four - way electromagnetic directional control valve 4 through a pipeline. The port T of the three - position four - way electromagnetic directional control valve 4 is communicated with the atmosphere.

[0012] The rodless end air inlet of any one of the support leg cylinders 2 is respectively connected to the high - pressure chamber 14 through an outlet pipe. A high - pressure check valve 8 is provided on the outlet pipe. The high - pressure check valve 8 allows gas to flow from the support leg cylinder 2 to the high - pressure chamber 14. The high - pressure chamber 14 is respectively connected to the port A of the two - position two - way electromagnetic directional control valve 6 through a pipeline. The other port of the two - position two - way electromagnetic directional control valve 6 is communicated with the atmosphere.

[0013] The air outlet end of the overflow valve 10 is connected to the high-pressure chamber 14 through a high-pressure intake pipe, and a high-pressure intake check valve 9 is provided on the high-pressure intake pipe. The high-pressure intake check valve 9 allows gas to flow from the air pump 3 to the high-pressure chamber 14;

[0014] The control system includes an infrared distance sensor 12 installed at the central position of the support arm 1, a first pressure sensor 13 for detecting the internal air pressure of the low-pressure chamber 7, a second pressure sensor 15 for detecting the internal air pressure of the high-pressure chamber 14, a third pressure sensor 16 for detecting the air pressure at the interface A of the three-position four-way electromagnetic directional valve 4, and a controller;

[0015] The signal input ends of the controller are respectively connected to the infrared distance sensor 12, the first pressure sensor 13, the second pressure sensor 15, and the third pressure sensor 16; the signal output ends of the controller are respectively connected to the air pump 3, the three-position four-way electromagnetic directional valve 4, and the two-position two-way electromagnetic directional valve 6.

[0016] In some solutions, the controller includes a sensor signal processing module 201, a driving module 202, an MCU 203, and a power supply module 204; the sensor signal processing module 201 collects and arranges signals from the sensors and transmits them to the MCU 203. After receiving signals that meet the conditions, the MCU 203 transmits control signals to the driving module 202, and the driving module 202 drives the air pump 3, the three-position four-way electromagnetic directional valve 4, and the two-position two-way electromagnetic directional valve 6 to act;

[0017] The power supply module 204 is connected to a DC power supply to supply power to the entire control system.

[0018] In some solutions, the support arm 1 is in a cross shape.

[0019] This application also provides a landing control method for a vertical takeoff and landing aircraft self-balancing landing gear system based on the above;

[0020] In the landing mode, the controller detects the height of the landing gear through the infrared distance sensor 12. When the height of the landing gear is lower than the height threshold H LWhen the vertical takeoff and landing aircraft hovers, the controller controls the air pump 3 to start. At this time, the three-position four-way electromagnetic directional valve 4 is in the off state, and the two-position two-way electromagnetic directional valve 6 is not powered on, and the valve is closed. The air pump 3 pumps air into the high-pressure chamber 14. When the controller detects through the second air pressure sensor 15 that the air pressure in the high-pressure chamber 14 is greater than the air pressure threshold value Pa, it controls the interface B of the three-position four-way electromagnetic directional valve 4 to communicate with the interface P, and the interface A to communicate with the interface T. Since the air pressure in the high-pressure chamber 14 is high, the air pump 3 no longer pumps air into the high-pressure chamber 14, but pumps air into the low-pressure chamber 7 with low air pressure. When the piston rods of the four support leg cylinders 2 are slowly pushed out, since the rodless chambers of the four support leg cylinders 2 are connected to the low-pressure chamber 7 together, the piston rods of the support leg cylinders 2 are subjected to the same gas pressure. When some piston rods first contact the ground, the piston rods of the other support leg cylinders 2 will continue to extend and contact the ground in turn. When the piston rods of all four support leg cylinders 2 contact the ground, the air pump 3 continues to supply air to increase the air pressure in the low-pressure chamber 7. The controller detects through the first air pressure sensor 13 that the air pressure in the low-pressure chamber 7 is greater than the air pressure threshold value P b When it reaches this value, the air pump 3 is turned off. At this time, the vertical takeoff and landing aircraft can stop.

[0021] In the takeoff mode described above, the vertical takeoff and landing aircraft starts to take off. When the controller detects through the infrared distance sensor 12 that the height of the landing gear is greater than the height threshold value H T When it reaches this value, it controls the two-position two-way electromagnetic directional valve 6 to be powered on, controls the interface A of the three-position four-way electromagnetic directional valve to communicate with the interface P, and the interface B to communicate with the interface T. At the same time, the air pump 3 pumps air into the rod chambers of the support leg cylinders 2. At this time, the air pressure in the high-pressure chamber 14 rapidly decreases to the atmospheric pressure, and the gas pressure in the support leg cylinders 2 can push the valve core of the high-pressure one-way valve 8, and the gas can be discharged through the high-pressure chamber 14. When the controller detects through the third air pressure sensor 16 that the air pressure at the interface A of the three-position four-way electromagnetic directional valve 4 is higher than the air pressure threshold value P C When it reaches this value, it controls the two-position two-way electromagnetic directional valve 6 to be powered off. The gas is discharged, and the piston rod retracts to the limit.

[0022] In some solutions, the height threshold value H L is 0.35 m; the air pressure threshold value P a is 0.55 MPa; the air pressure threshold value P b is 0.4 MPa; the air pressure threshold value P C is 0.15 MPa.

[0023] The technical solution provided by the present invention may include the following beneficial effects:

[0024] 1. The landing gear of the present invention has a large adjustable range and strong adaptability to uneven ground, can ensure that the vertical takeoff and landing aircraft lands on a non-flat road surface, avoid the risk of rollover or even capsizing when the aircraft lands on uneven ground, and improve the landing stability and safety.

[0025] 2. The landing gear of the present invention adopts pneumatic control, with a simple system structure, no complex internal components, and a lighter mass. By connecting the four cylinders to the common low-pressure chamber, independent control of the four cylinders is not required, and the adaptive adjustment of the support feet can be achieved to keep the vertical takeoff and landing aircraft land horizontally.

[0026] 4. After the cylinder feet of the landing gear system of the present invention all touch the ground, it has good support for the aircraft and can achieve zero-impact landing of the aircraft.

[0027] 7. The control medium of the landing gear system of the present invention is air, which can be directly sourced from the atmosphere, not only cost-free but also without causing environmental pollution.

[0028] 5. The present invention expands the application range of vertical takeoff and landing aircraft in scenarios such as the wild, mountains, and ruins, and improves the reliability and practicality of vertical takeoff and landing aircraft in diverse tasks.

[0029] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more apparent. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0031] Figure 1 is a schematic structural diagram of the landing gear shown in the embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of a pipeline connection of the landing gear shown in the embodiment of the present invention;

[0033] Figure 3 is another schematic diagram of a pipeline connection of the landing gear shown in the embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of the pressure during the process of the piston rod of the support leg cylinder of the landing gear shown in the embodiment of the present invention extending;

[0035] Figure 5 is a schematic diagram of the pressure during the process of the piston rod of the support leg cylinder of the landing gear shown in the embodiment of the present invention retracting;

[0036] Figure 6 is a schematic structural diagram of the controller of the landing gear system shown in the embodiment of the present invention;

[0037] Figure 7 Schematic diagram of the control logic during the landing process in the landing control method of the landing gear system shown in the embodiment of the present invention;

[0038] Figure 8 Schematic diagram of the take-off process control logic in the landing control method of the landing gear system shown in the embodiments of the present invention;

[0039] Reference numerals:

[0040] 1. Support arm; 2. Leg cylinder; 3. Air pump; 4. Three-position four-way electromagnetic directional control valve; 5. Low-pressure check valve; 6. Two-position two-way electromagnetic directional control valve; 7. Low-pressure chamber; 8. High-pressure check valve; 9. High-pressure intake check valve; 10. Relief valve; 11. Throttle valve; 12. Infrared distance sensor; 13. First pressure sensor; 14. High-pressure chamber; 15. Second pressure sensor; 16. Third pressure sensor. Detailed implementation manners

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the described content.

[0042] Please refer to Figure 1 and Figure 2 , the present application provides a self-balancing landing gear for a vertical take-off and landing aircraft. The self-balancing landing gear is applicable to vertical take-off and landing aircraft, such as rotor unmanned aerial vehicles, helicopters, etc. The landing gear includes a support arm 1, a leg cylinder 2, an air pump 3, a three-position four-way electromagnetic directional control valve 4, a low-pressure check valve 5, and a two-position two-way electromagnetic directional control valve 6.

[0043] The fuselage of the aircraft is mounted on the support arm 1. At least three leg cylinders 2 are provided at the bottom of the support arm 1 as the main supporting components in contact with the ground, and a three-point layout, a four-point layout or a multi-point layout is formed; preferably, the support arm 1 is in a cross shape, and four leg cylinders 2 are provided, which are respectively located at the ends of the support arm 1.

[0044] A low-pressure chamber 7 is provided inside the support arm 1; the air pump 3 is provided on the support arm 1, and the output end of the air pump 3 is connected to the port P of the three-position four-way electromagnetic directional control valve 4 through a pipeline, and the port B of the three-position four-way electromagnetic directional control valve 4 is connected to the low-pressure chamber 7 through a pipeline; the rodless end air inlet of any one of the leg cylinders 2 is connected to the low-pressure chamber 7 through an intake pipe, and a low-pressure check valve 5 is provided on the intake pipe, and the low-pressure check valve 5 allows gas to flow from the low-pressure chamber 7 to the leg cylinder 2.

[0045] The rodless end air inlet of any one of the leg cylinders 2 is respectively connected to the port A of the two-position two-way electromagnetic directional control valve 6 through a pipeline, and the other end of the two-position two-way electromagnetic directional control valve 6 is communicated with the atmosphere; the rod end air inlet of any one of the leg cylinders 2 is connected to the port A of the three-position four-way electromagnetic directional control valve 4 through a pipeline, and the port T of the three-position four-way electromagnetic directional control valve 4 is communicated with the atmosphere.

[0046] It should be known that the three-position four-way solenoid directional control valve 4 has three working states: First, port P is connected to port A, and port B is connected to port T; Second, port P is connected to port B, and port A is connected to port T; Third, ports P, A, B, and T are all in the off state.

[0047] When the aircraft is in flight, all the outrigger cylinders 2 are in the retracted state; the three-position four-way solenoid directional control valve 4 is in the cut-off position, that is, ports P, A, B, and T are all in the off state; the two-position two-way solenoid directional control valve 6 is in the closed state.

[0048] When the aircraft is about to land, the aircraft approaches the ground and is in a hovering state. The hovering height from the ground is less than the effective stroke of the outrigger cylinder 2. Subsequently, the three-position four-way solenoid directional control valve 4 operates to connect its port P to port B and port A to port T; then the air pump 3 operates to pump out the gas. The gas enters the low-pressure chamber 7 after passing through the pipeline and the three-position four-way solenoid directional control valve 4, and is then distributed by the low-pressure chamber 7 and introduced into each outrigger cylinder 2 respectively, driving each outrigger cylinder 2 to extend. During the extension process of each outrigger cylinder 2, if there are undulations on the ground, some outrigger cylinders 2 will contact the ground first and require a greater air pressure to continue extending, while the outrigger cylinders 2 that have not contacted the ground continue to extend until all outrigger cylinders 2 contact the ground. Then the air pressure in the low-pressure chamber 7 gradually rises. When the air pressure in the low-pressure chamber 7 reaches the set pressure, the outrigger cylinders 2 can provide stable support for the aircraft, and the aircraft is controlled to stop to complete the landing of the aircraft.

[0049] During the above-mentioned aircraft landing process, at the moment when the boom 1 of the aircraft contacts the ground, it does not bear the gravity of the aircraft itself. Therefore, it is hardly affected by the impact force, effectively improving the service life of the landing gear. Moreover, when the aircraft stops, the boom 1 can already provide sufficient support force for the aircraft. The impact force on the aircraft only comes from the possible vertical displacement caused by the air compression inside the outrigger cylinder 2. The impact force generated during the aircraft landing is extremely small, effectively improving the safety of the aircraft during landing. At the same time, it makes the aircraft landing process smoother and improves the comfort of the aircraft during landing; in this application, the setting of the low-pressure check valve 5 makes it so that when the aircraft is parked stably, if the center of gravity of the aircraft shifts to one side, the outrigger cylinder 2 on the corresponding side will not contract, thus ensuring the stability of the aircraft during the docking process.

[0050] Furthermore, in the present application, by providing a low-pressure chamber 7, each leg cylinder 2 can be extended to a length adapted to the ground through the low-pressure chamber 7, so as to achieve the purpose of stable landing. Compared with the traditional bionic multi-legged landing gear, in the present application, it is not necessary to accurately obtain the distance between each support leg and the ground when the aircraft is in a hovering state, and accurately adjust the length of each support leg to adapt to the ground, effectively reducing the control difficulty and not requiring a powerful computing ability, thus reducing the manufacturing cost of the landing gear.

[0051] When the aircraft is in transportation and storage, the pressure in the low-pressure chamber 7 can be increased to a relatively large value, so that all the leg cylinders 2 can be fully extended to the limit distance, thus ensuring the stability of the aircraft during transportation and storage.

[0052] After the aircraft takes off and leaves the ground or when it is necessary to retract the leg cylinders 2, the two-position two-way electromagnetic directional control valve 6 is opened to discharge the high-pressure air in the rodless chamber and the high-pressure chamber 14 of the leg cylinders 2; the three-position four-way electromagnetic directional control valve 4 operates to connect its port P with port A and port B with port T; the air pump 3 operates to pump air into the rod chamber of the leg cylinders 2, thereby driving the telescopic rod of the cylinder to retract.

[0053] In some specific embodiments, such as Figure 1 、 Figure 3 、 Figure 4 and Figure 5 as shown, a high-pressure chamber 14 is provided in the support arm 1; the rodless end air inlet of any one of the leg cylinders 2 is respectively connected to the high-pressure chamber 14 through an air outlet pipe, and a high-pressure one-way valve 8 is provided on the air outlet pipe, and the high-pressure one-way valve 8 allows gas to flow from the leg cylinder 2 to the high-pressure chamber 14, and the high-pressure chamber 14 is connected to the two-position two-way electromagnetic directional control valve 6 through a pipeline; the air pump 3 is connected to the high-pressure chamber 14 through a high-pressure air inlet pipe, and a high-pressure air inlet one-way valve 9 is provided on the high-pressure air inlet pipe, and the high-pressure air inlet one-way valve 9 allows gas to flow from the air pump 3 to the high-pressure chamber 14.

[0054] When the aircraft is about to land and before the three-position four-way electromagnetic directional control valve 4 operates, the air pump 3 operates first, and air is introduced into the high-pressure chamber 14 through a pipeline and a high-pressure single-way intake valve, so that the air pressure in the high-pressure chamber 14 rises until the pressure in the high-pressure chamber 14 rises to a set pressure greater than the pressure in the cylinder when the aircraft is supported by the leg cylinders 2. Subsequently, the three-position four-way electromagnetic directional control valve 4 operates to connect its port P with port B and port A with port T; at this time, since the high-pressure chamber 14 is in a high-pressure state, the air discharged by the air pump 3 enters the low-pressure chamber 7 and is distributed to each leg cylinder 2 through the low-pressure chamber 7 until each leg cylinder 2 can provide stable support for the aircraft.

[0055] Thus, the rodless chamber of the outrigger cylinder 2 is connected to a high-pressure chamber 14 with a high pressure. When the aircraft stops, the weight of the aircraft is transferred to the support arm 1, and the outrigger cylinder 2 is compressed. The air pressure inside its rod chamber increases, but it is still less than the internal pressure of the high-pressure chamber 14, so that the air inside the outrigger cylinder 2 will not be discharged. Thereby, the amplitude of the length reduction of the outrigger cylinder 2 caused by the compression of the air inside it when it is compressed is reduced, and further the amplitude of the height change of the aircraft after it stops is reduced, improving the landing stability and comfort of the aircraft.

[0056] In this embodiment, a relief valve 10 is provided on the connecting pipe between the air pump 3 and the three-position four-way electromagnetic directional control valve 4; the intake end of the high-pressure intake check valve 9 is connected to the outlet end of the relief valve 10. It is used to limit the maximum value of the output pressure of the air pump 3 and protect the pneumatic system. Specifically, the relief valve 10 uses the valve core under the action of the spring to open or close the valve. When the air pressure exceeds the preset maximum pressure, the valve core moves under the action of the pressure to overcome the spring force, and the valve opens, and the air is discharged, so that the air pump 3 or the pneumatic circuit components will not be damaged due to overload.

[0057] In this embodiment, a throttle valve 11 is provided on the connecting pipe between the three-position four-way electromagnetic directional control valve 4 and the low-pressure chamber 7. The speed is adjusted by changing the valve port area. Specifically, the throttle valve 11 makes the valve core move relative to the valve body hole by means of a control mechanism to change the flow area of the valve port, and realizes speed regulation in the circuit. That is, by controlling the valve port area of the throttle valve 11, the speed of the piston rod of the outrigger cylinder 2 extending out can be controlled.

[0058] Based on the above vertical takeoff and landing aircraft self-balancing landing gear, the present application also provides a vertical takeoff and landing aircraft self-balancing landing gear system, including the above landing gear, a control system, and a DC power supply. The DC power supply is used to provide energy for the landing gear and the control system.

[0059] The control system includes an infrared distance sensor 12 installed at the central position of the support arm 1, a first pressure sensor 13 for detecting the internal air pressure of the low-pressure chamber 7, a second pressure sensor 15 for detecting the internal air pressure of the high-pressure chamber 14, a third pressure sensor 16 for detecting the air pressure at the interface A of the three-position four-way electromagnetic directional control valve 4, and a controller.

[0060] During landing, the infrared distance sensor 12 roughly detects the distance between the aircraft and the ground and transmits relevant data to the controller. When the distance between the aircraft and the ground is less than the stroke of the outrigger cylinder 2 and the fuselage has not yet touched the ground, the controller controls the air pump 3, the three-position four-way electromagnetic directional control valve 4, etc. to work to execute the landing procedure; the first pressure sensor 13 transmits the pressure data P in the low-pressure chamber 7 bTransmitted to the controller, so that the controller can determine whether the air pressure in the low-pressure chamber 7 reaches the set pressure; the second pressure sensor 15 transmits the pressure data P in the high-pressure chamber 14 a to the controller, so that the controller can determine whether the air pressure in the high-pressure chamber 14 reaches the set pressure.

[0061] In this embodiment, as Figure 6 shown, the controller includes a sensor signal processing module 201, a driving module 202, an MCU 203, and a power supply module 204; the sensor signal processing module 201 collects and processes signals from the sensors and transmits them to the MCU 203. After receiving signals that meet the conditions, the MCU 203 transmits control signals to the driving module 202, and the driving module 202 drives the air pump 3, the three-position four-way electromagnetic directional valve 4, and the two-position two-way electromagnetic directional valve 6 to act;

[0062] The power supply module 204 is connected to the DC power supply to supply power to the entire control system.

[0063] Based on the above vertical takeoff and landing aircraft self-balancing landing gear system, the present application also provides a landing control method for a vertical takeoff and landing aircraft self-balancing landing gear system.

[0064] In the landing mode, as Figure 7 shown, the controller detects the height of the landing gear through the infrared distance sensor 12. When the height of the landing gear is lower than the height threshold H L , the vertical takeoff and landing aircraft hovers, and the controller controls the air pump 3 to start. At this time, the three-position four-way electromagnetic directional valve 4 is in the off state, the two-position two-way electromagnetic directional valve 6 is not energized, the valve is closed, and the air pump 3 pumps air into the high-pressure chamber 14; when the controller detects through the second pressure sensor 15 that the air pressure in the high-pressure chamber 14 is greater than the air pressure threshold Pa, it controls the interface B of the three-position four-way electromagnetic directional valve 4 to communicate with the interface P, and the interface A to communicate with the interface T; since the air pressure in the high-pressure chamber 14 is high, the air pump 3 no longer pumps air into the high-pressure chamber 14, but pumps air into the low-pressure chamber 7 with low air pressure; when the piston rods of the four support leg cylinders 2 are slowly pushed out, since the rodless chambers of the four support leg cylinders 2 are connected to the low-pressure chamber 7 together, the piston rods of the support leg cylinders 2 are subjected to the same gas pressure; when some piston rods first contact the ground, the piston rods of the other support leg cylinders 2 will continue to extend and contact the ground in turn; when the piston rods of the four support leg cylinders 2 all contact the ground, the air pump 3 continues to supply air to increase the air pressure in the low-pressure chamber 7. When the controller detects through the first pressure sensor 13 that the air pressure in the low-pressure chamber 7 is greater than the air pressure threshold P b , the air pump 3 is turned off; at this time, the vertical takeoff and landing aircraft can stop.

[0065] During the landing process of the above-mentioned aircraft, at the moment when the outrigger 1 of the aircraft contacts the ground, it does not bear the gravity of the aircraft itself. Therefore, it is hardly affected by the impact force, effectively improving the service life of the landing gear. Moreover, when the aircraft is parked, the outrigger 1 can already provide sufficient support force for the aircraft. The impact force generated during the landing of the aircraft is extremely small, effectively improving the safety during the landing of the aircraft. At the same time, the landing process of the aircraft is made smoother, improving the comfort during the landing of the aircraft.

[0066] Furthermore, in this application, by setting the low-pressure chamber 7, each outrigger cylinder 2 can be extended to a length adapted to the ground through the low-pressure chamber 7, so as to achieve the purpose of stable landing. Compared with the traditional bionic multi-legged landing gear, this application does not need to accurately obtain the distance between each support leg and the ground when the aircraft is in a hovering state, and accurately adjust the length of each support leg to be adapted to the ground, effectively reducing the control difficulty and not requiring a powerful computing ability, reducing the manufacturing cost of the landing gear.

[0067] In the takeoff mode, as Figure 8 shown, the vertical takeoff and landing aircraft starts to take off; when the controller detects through the infrared distance sensor 12 that the height of the landing gear is greater than the height threshold H T the two-position two-way electromagnetic reversing valve 6 is controlled to be energized, the interface A of the three-position four-way electromagnetic reversing valve is controlled to communicate with the interface P, and the interface B is communicated with the interface T. At the same time, the air pump 3 pumps air into the rod chamber of the outrigger cylinder 2; at this time, the air pressure in the high-pressure chamber 14 rapidly decreases to the atmospheric pressure, and the gas pressure in the outrigger cylinder 2 can push the valve core of the high-pressure one-way valve 8, and the gas can be discharged through the high-pressure chamber 14; when the controller detects through the third air pressure sensor 16 that the air pressure at the interface A of the three-position four-way electromagnetic reversing valve 4 is higher than the air pressure threshold P C the two-position two-way electromagnetic reversing valve 6 is controlled to be de-energized; the gas is discharged, and the piston rod retracts to the limit.

[0068] In this embodiment, the height threshold HL is 0.35 m; the air pressure threshold Pa is 0.55 MPa; the air pressure threshold Pb is 0.4 MPa; the air pressure threshold PC is 0.15 MPa.

[0069] In some specific embodiments, the present invention can also achieve self-balanced landing by changing the medium, such as using hydraulic oil as the medium; the vertical takeoff and landing aircraft can be installed on the outrigger of the landing gear or the landing gear system can be integrally designed with the vertical takeoff and landing aircraft; the size of the landing gear system can be matched according to the size of the vertical takeoff and landing aircraft, and the pressure threshold of the control system can be determined according to the pushing pressure of the landing gear cylinder

[0070] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A vertical takeoff and landing aircraft self-balancing landing gear system, characterized in that: It includes a landing gear, a control system, and a DC power supply, and the DC power supply is used to provide energy for the landing gear and the control system; The landing gear includes a support arm (1), four support leg cylinders (2), an air pump (3), a three-position four-way electromagnetic directional control valve (4), a low-pressure check valve (5), and a two-position two-way electromagnetic directional control valve (6); The four support leg cylinders (2) are respectively installed at the ends of the support arm (1), and a hidden low-pressure chamber (7) and a high-pressure chamber (14) are provided inside the support arm (1); The air pump (3) is arranged on the support arm (1), the output end of the air pump (3) is connected to the port P of the three-position four-way electromagnetic directional control valve (4) through a pipeline, and an overflow valve (10) is also provided on the connecting pipeline between the air pump (3) and the three-position four-way electromagnetic directional control valve (4); the port B of the three-position four-way electromagnetic directional control valve (4) is connected to the low-pressure chamber (7) through a pipeline, and a throttle valve (11) is provided on the connecting pipeline between the three-position four-way electromagnetic directional control valve (4) and the low-pressure chamber (7); the rodless end air inlet of any one of the support leg cylinders (2) is connected to the low-pressure chamber (7) through an intake pipe, and a low-pressure check valve (5) is provided on the intake pipe, and the low-pressure check valve (5) allows gas to flow from the low-pressure chamber (7) to the support leg cylinder (2); The rod end air inlet of any one of the support leg cylinders (2) is connected to the port A of the three-position four-way electromagnetic directional control valve (4) through a pipeline, and the port T of the three-position four-way electromagnetic directional control valve (4) is communicated with the atmosphere; The rodless end air inlet of any one of the support leg cylinders (2) is respectively connected to the high-pressure chamber (14) through an exhaust pipe, and a high-pressure check valve (8) is provided on the exhaust pipe, and the high-pressure check valve (8) allows gas to flow from the support leg cylinder (2) to the high-pressure chamber (14), and the high-pressure chamber (14) is respectively connected to the port A of the two-position two-way electromagnetic directional control valve (6) through a pipeline; the other port of the two-position two-way electromagnetic directional control valve (6) is communicated with the atmosphere; The air outlet end of the overflow valve (10) is connected to the high-pressure chamber (14) through a high-pressure intake pipe, and a high-pressure intake check valve (9) is provided on the high-pressure intake pipe, and the high-pressure intake check valve (9) allows gas to flow from the air pump (3) to the high-pressure chamber (14); The control system includes an infrared distance sensor (12) installed at the central position of the support arm (1), a first pressure sensor (13) for detecting the internal air pressure of the low-pressure chamber (7), a second pressure sensor (15) for detecting the internal air pressure of the high-pressure chamber (14), a third pressure sensor (16) for detecting the air pressure of the port A of the three-position four-way electromagnetic directional control valve (4), and a controller; The signal input ends of the controller are respectively connected to the infrared distance sensor (12), the first pressure sensor (13), the second pressure sensor (15), and the third pressure sensor (16); the signal output ends of the controller are respectively connected to the air pump (3), the three-position four-way electromagnetic directional control valve (4), and the two-position two-way electromagnetic directional control valve (6).

2. The self-balancing landing gear system for a vertical takeoff and landing aircraft according to claim 1, wherein: The controller includes a sensor signal processing module (201), a driving module (202), an MCU (203), and a power supply module (204); the sensor signal processing module (201) collects and processes signals from sensors and transmits them to the MCU (203). After receiving signals that meet the conditions, the MCU (203) transmits control signals to the driving module (202), and the driving module (202) drives the air pump (3), the three-position four-way electromagnetic directional control valve (4), and the two-position two-way electromagnetic directional control valve (6) to act; The power supply module (204) is connected to a DC power supply to supply power to the entire control system.

3. The self-balancing landing gear system of a vertical takeoff and landing aircraft according to claim 1, wherein: The support arm (1) is in a cross shape.

4. A landing control method for a self-balancing landing gear system of a vertical takeoff and landing aircraft according to any one of claims 1-3, wherein: In the landing mode, the controller detects the height of the landing gear through the infrared distance sensor (12). When the height of the landing gear is lower than the height threshold H L the vertical takeoff and landing vehicle hovers, and the controller controls the air pump (3) to start. At this time, the three-position four-way electromagnetic directional valve (4) is in the off state, the two-position two-way electromagnetic directional valve (6) is not energized, the valve is closed, and the air pump (3) pumps air into the high-pressure chamber (14). When the controller detects through the second air pressure sensor (15) that the air pressure in the high-pressure chamber (14) is greater than the air pressure threshold P a it controls the interface B of the three-position four-way electromagnetic directional valve (4) to communicate with the interface P, and the interface A to communicate with the interface T. Since the air pressure in the high-pressure chamber (14) is high, the air pump (3) no longer pumps air into the high-pressure chamber (14), but pumps air into the low-pressure chamber (7) with low air pressure. When the piston rods of the four outrigger cylinders (2) are slowly pushed out, since the rodless chambers of the four outrigger cylinders (2) are connected to the low-pressure chamber (7) together, the piston rods of the outrigger cylinders (2) are subjected to the same gas pressure. When some piston rods first touch the ground, the piston rods of the other outrigger cylinders (2) will continue to extend and touch the ground in turn. After the piston rods of the four outrigger cylinders (2) all touch the ground, the air pump (3) continues to supply air to increase the air pressure in the low-pressure chamber (7). When the controller detects through the first air pressure sensor (13) that the air pressure in the low-pressure chamber (7) is greater than the air pressure threshold P b the air pump (3) is turned off. At this time, the vertical takeoff and landing vehicle can stop. In the takeoff mode, the vertical takeoff and landing vehicle starts to take off; when the controller detects through the infrared distance sensor (12) that the height of the landing gear is greater than the height threshold H T , the two-position two-way electromagnetic reversing valve (6) is controlled to be energized, the interface A of the three-position four-way electromagnetic reversing valve (4) is controlled to communicate with the interface P, the interface B is communicated with the interface T, and the air pump (3) pumps air into the rodless cavity of the outrigger cylinder (2); at this time, the air pressure in the high-pressure chamber (14) rapidly decreases to the atmospheric pressure, and the gas pressure in the outrigger cylinder (2) can push the spool of the high-pressure check valve (8), and the gas can be discharged through the high-pressure chamber (14); when the controller detects through the third air pressure sensor (16) that the air pressure at the interface A of the three-position four-way electromagnetic reversing valve (4) is higher than the air pressure threshold P C , the two-position two-way electromagnetic reversing valve (6) is controlled to be de-energized; the gas is discharged, and the piston rod retracts to the limit.

5. The landing control method according to claim 4, wherein: Height threshold H L is 0.35 m; Air pressure threshold P a is 0.55 MPa; Air pressure threshold P b is 0.4 MPa; Air pressure threshold P C is 0.15 MPa.

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