Unmanned aerial vehicle recycling system based on multi-stage buffering and control method

Abstract

The unmanned aerial vehicle recovery system comprises an unmanned aerial vehicle, and a main control system, a sensor system and a power supply system used for supplying power to the unmanned aerial vehicle are fixedly installed in the unmanned aerial vehicle; the power system comprises a main power supply and an emergency power supply; an airbag component is arranged at the bottom of the body of the unmanned aerial vehicle; a lift assembly is arranged on the top of the unmanned aerial vehicle body. Multiple parachute assemblies are symmetrically arranged on the two sides of a fuselage of the unmanned aerial vehicle. The sensor system monitors operation parameters of the unmanned aerial vehicle and feeds back the operation parameters to the master control system. The master control system receives signals of the sensor system and controls operation of the airbag assembly, the lift assembly and the parachute assembly. The technical problem that an existing unmanned aerial vehicle recycling system cannot meet the high-low-altitude recycling requirement is solved, and the technical effect of being suitable for high-altitude recycling and low-altitude recycling at the same time is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned aerial vehicle recovery, in particular to an unmanned aerial vehicle recovery system based on multi-stage buffering and a control method. BACKGROUND

[0002] Currently, civil unmanned aerial vehicles are widely used in various industries. Unmanned aerial vehicles have been deeply integrated into city management, logistics distribution, agricultural plant protection, emergency rescue and other diversified scenarios due to their flexibility and low-altitude operation capability. In the field of agricultural plant protection, 20kg unmanned aerial vehicles are commonly used. Unmanned aerial vehicles need to operate at a low altitude of 1-3 meters above the crop top and climb to a height of dozens of meters for transfer cruising when switching operation plots. Therefore, unmanned aerial vehicles need to switch between high-altitude and low-altitude operations.

[0003] In daily life, unmanned aerial vehicles are remotely controlled by people, so there is a certain degree of operation difficulty and visual blind area. In actual low-altitude operation, unmanned aerial vehicles often lose balance due to collisions with branches, power lines and other obstacles, ultimately leading to falling. In actual high-altitude operation, unmanned aerial vehicles will not fall due to collisions with obstacles, but there is a problem of falling from high altitude due to power failure.

[0004] In the prior art, for unmanned aerial vehicles operating at low altitudes, mechanical buffering structures such as airbags are usually provided at the bottom of the unmanned aerial vehicles to buffer the unmanned aerial vehicles falling from low altitudes. For unmanned aerial vehicles operating at altitudes of dozens of meters, parachutes are usually provided to assist in soft landing.

[0005] However, for unmanned aerial vehicles that have both high-altitude and low-altitude operating environments, if airbags are provided alone, the impact force cannot be effectively alleviated due to insufficient compression stroke of the airbags after falling from high altitudes due to power failure. If parachutes are provided alone, the parachute system cannot effectively slow down when falling from low altitudes. If airbags and parachutes are provided simultaneously, there are problems such as increase in weight of the unmanned aerial vehicle, difficulty in controlling the timing of airbag inflation and parachute opening, leading to conflicts between the two, failure of recovery, and even misjudgment of landing and falling, making it difficult to achieve safe recovery of unmanned aerial vehicles that have both high-altitude and low-altitude operating requirements.

[0006] Therefore, it is necessary to design an unmanned aerial vehicle recovery system suitable for both high-altitude and low-altitude environments. SUMMARY

[0007] The present application provides an unmanned aerial vehicle recovery system based on multi-stage buffering and a control method, which solves the technical problem that existing unmanned aerial vehicle recovery systems cannot meet the requirements of high and low altitude recovery.

[0008] The application provides a multi-stage buffer-based unmanned aerial vehicle recovery system, which comprises an unmanned aerial vehicle, a main control system, a sensor system and a power supply system for supplying power to the unmanned aerial vehicle are fixedly installed in the unmanned aerial vehicle; the power supply system comprises a main power supply and an emergency power supply; a gas bag assembly is arranged at the bottom of the fuselage of the unmanned aerial vehicle; a lifting assembly is arranged at the top of the fuselage of the unmanned aerial vehicle; a plurality of parachute assemblies are symmetrically arranged at the two sides of the fuselage of the unmanned aerial vehicle; the sensor system monitors the operating parameters of the unmanned aerial vehicle and feeds back to the main control system, and the main control system receives the signals of the sensor system and controls the operation of the gas bag assembly, the lifting assembly and the parachute assembly.

[0009] By adopting the technical scheme, the multi-stage buffer recovery system composed of the main control system, the sensor system, the power supply system, the gas bag assembly, the lifting assembly and the parachute assembly is arranged on the unmanned aerial vehicle, the data monitored by the sensor system is determined by the main control system to realize automatic judgment of high and low altitude faults of the unmanned aerial vehicle and operation of corresponding recovery programs, the problem that the existing recovery system cannot simultaneously meet the high and low altitude recovery requirements is effectively solved, and through the coordinated control of the main control system, the orderly operation of the components is realized, time sequence conflicts are avoided, and safe recovery of the unmanned aerial vehicle in the case of power failure or collision out of control is ensured.

[0010] Preferably, the sensor system comprises an attitude sensor for monitoring acceleration, a current detection sensor for monitoring current change and an air pressure sensor for monitoring descent rate, the attitude sensor is arranged in the fuselage of the unmanned aerial vehicle, the current detection sensor is arranged in the power supply loop of the unmanned aerial vehicle, and the air pressure sensor is arranged at the air vent on one side of the fuselage of the unmanned aerial vehicle.

[0011] By adopting the technical scheme, the attitude sensor, the current detection sensor and the air pressure sensor are integrated to form a complete sensor system, real-time and reliable flight state data is provided for the main control system of the unmanned aerial vehicle, the detection of power failure by the current detection sensor and the detection of descent rate by the air pressure sensor greatly improve the accuracy and timeliness of identification of two key fault modes, power failure and collision out of control, data support is provided for subsequent correct start of corresponding multi-stage buffer recovery programs, and the risk of misjudgment is effectively reduced.

[0012] Preferably, the gas bag assembly comprises a first support and six first gas bags in compressed states, the first support is arranged at the bottom of the fuselage of the unmanned aerial vehicle, the six first gas bags in compressed states are connected in sequence in a ring shape and arranged around the bottom of the fuselage of the unmanned aerial vehicle, and each first gas bag is connected with the first support, and a first gas generating pot for rapid inflation and expansion is arranged at the inflation port of each first gas bag in compressed state.

[0013] By adopting the above technical scheme, six compressed first air bags are arranged in a ring around the bottom of the fuselage, are fixed on the first support, and are respectively provided with independent first gas generating tanks, the ring-shaped air bag design can form a comprehensive ring-shaped buffer surface on the bottom of the unmanned aerial vehicle after inflation and expansion, and can preliminarily buffer and slow down the unmanned aerial vehicle in falling, and the ring-shaped combination of multiple air bags can better adapt to uneven ground than a single large air bag, and the independent gas tank in each air bag ensures the inflation and expansion speed, and can ensure instantaneous and simultaneous expansion, thereby providing timely and effective preliminary physical buffer and protection for the unmanned aerial vehicle in the initial stage of low-altitude collision or high-altitude falling.

[0014] Preferably, the six first air bags are connected in a head-to-tail manner through magnetic attraction type quick release interfaces, the inflation openings of two adjacent first air bags are arranged at the head end, and the inflation openings of the other four first air bags are arranged at the tail end.

[0015] By adopting the above technical scheme, the flow directions of the gas flows in the two first air bags are opposite to those in the other four first air bags, the asymmetric air chamber design makes the air bags generate gyroscopic effect after expansion, realizes self-stabilization of the unmanned aerial vehicle in the falling process, and avoids damage caused by turning over of the unmanned aerial vehicle in falling.

[0016] Preferably, the lift assembly comprises a connecting belt, a second air bag and a third air bag, the connecting belt is used for connecting the second air bag and the third air bag, the second air bag is provided with a second gas generating tank for filling helium or hydrogen, the third air bag is provided with a third gas generating tank for rapid inflation, the third air bag is provided with a first electric heating wire for heating gas, the first electric heating wire is electrically connected with the main control system, and the second air bag is provided with a gas release valve electrically connected with the main control system.

[0017] By adopting the above technical scheme, the second air bag filled with light gas provides stable static buoyancy to significantly slow down the unmanned aerial vehicle, the third air bag generates hot buoyancy by rapid inflation and built-in electric heating wire, and the two work together to provide better lift effect than a single air bag or parachute in the initial stage, especially in the long-distance falling process after power failure at high altitude, more deceleration time can be effectively obtained, the speed and impact energy of the final parachute opening are greatly reduced, and the smoothness and safety of the entire recovery process are improved.

[0018] Preferably, the lift assembly further comprises a second support and a skeleton made of memory metal, one end of the skeleton is connected with the top end of the unmanned aerial vehicle body, the other end of the skeleton is connected with the second support, the connecting belt is connected with the second support, the second air bag in the compressed state and the third air bag in the compressed state are fixed on the second support, the skeleton is folded in a "Z" shape, and the skeleton is integrated with a second electric heating wire electrically connected with the main control system.

[0019] By adopting the technical scheme, the memory metal material Z-shaped folding framework integrated with the second electric heating wire is arranged, and the lift assembly is connected through the second support, when unfolding is needed, the main control system is powered on to heat the memory metal framework, so that the memory metal framework quickly restores the preset unfolded shape, and the second support, the second air bag and the third air bag are stably pushed to the safe unfolded position away from the fuselage, so that the lift assembly can be quickly and safely unfolded in the predetermined space, thereby providing stable buoyancy.

[0020] Preferably, two parachute assemblies are symmetrically arranged on the two sides of the unmanned aerial vehicle fuselage, each parachute assembly comprises a parachute cabin and a parachute bag, the upper end surface of the parachute cabin is provided with a hinged cabin door, each cabin door is controlled by a driving motor electrically connected with the main control system, each parachute bag is arranged in the parachute cabin, and an ejection plate for ejecting the parachute bag is arranged in each parachute cabin.

[0021] By adopting the technical scheme, two independent parachute assemblies are symmetrically arranged on the two sides of the fuselage, each assembly comprises a parachute cabin with a cabin door controlled by a driving motor, and an embedded parachute bag and an ejection plate, the symmetrical layout ensures the balance of the unmanned aerial vehicle attitude in the final landing stage; when the parachute needs to be opened, the driving motor opens the cabin door, and the ejection plate immediately ejects the parachute bag out of the cabin, so that the parachute can be smoothly and quickly stretched and filled in the airflow away from the fuselage, avoiding the opening failure caused by the entanglement of the parachute rope or the incomplete separation of the parachute cover from the machine body, and greatly improving the stability of the parachute assembly during recovery.

[0022] The application provides a control method of a multi-stage buffer-based unmanned aerial vehicle recovery system, which comprises the unmanned aerial vehicle recovery system and the following specific steps: S1, a sensor system monitors the operation state of the unmanned aerial vehicle and transmits monitoring data to a main control system; when the main control system monitors an abnormal operation state of the unmanned aerial vehicle, step S2 is entered; S2, the main control system judges the abnormal operation state of the unmanned aerial vehicle; if the sensor system monitors that the main power supply voltage is lower than a preset voltage value and the vertical acceleration of the unmanned aerial vehicle is greater than a first preset acceleration, an emergency power supply is activated to enter a warning program; if the sensor system monitors that the vertical acceleration is greater than a second preset acceleration within a first preset time period after the warning program is started, it is determined that the power failure is abnormal; if the sensor system monitors the lateral acceleration, it is determined that the collision out-of-control is abnormal; S3, corresponding programs are executed according to the determination result of step S2; if the power failure is abnormal, the main control system executes a power failure recovery program; after the sensor system monitors that the vertical acceleration is greater than a third preset acceleration within a second preset time period, the main control system first sends a signal to make the airbag assembly arranged at the bottom of the unmanned aerial vehicle body inflate and expand to buffer, then sends a signal to make the lift assembly arranged at the top of the unmanned aerial vehicle body inflate and expand and heat, and when the sensor system monitors that the height is stable, the main control system sends a signal to make the air release valve in the lift assembly start, and simultaneously sends a signal to make the multiple parachute assemblies arranged on both sides of the unmanned aerial vehicle body pop up and expand; if the collision out-of-control is abnormal, the main control system executes a collision out-of-control recovery program, and the main control system sends a signal to make the airbag assembly at the bottom of the unmanned aerial vehicle body inflate and expand, and simultaneously sends a signal to make the multiple parachute assemblies pop up and expand.

[0023] By adopting the technical scheme, the sensor system monitors the flight state in real time and transmits monitoring data to the main control system, the main control system determines two main fault modes of power failure and collision out-of-control according to the monitoring data, and triggers corresponding multi-stage buffer recovery programs, thereby effectively solving the problem that the existing recovery system cannot meet the high and low altitude recovery requirements; in the case of power failure, the bottom airbag assembly is first used for buffering, then the top lift assembly is expanded and heated to provide buoyancy, and finally the parachute is released to achieve soft landing when the height is stable, through the multi-stage time sequence cooperative design of the airbag assembly, the lift assembly and the parachute assembly, the long distance deceleration requirement of high altitude falling can be met, and the airbag assembly and the parachute assembly can be quickly started for joint buffering in the case of low altitude collision, the recovery success rate in the case of falling at different heights is significantly improved, and through the preset acceleration threshold and preset time period determination, system conflicts and resource waste caused by false triggering are effectively avoided.

[0024] The one or more technical solutions provided in the application have at least the following technical effects or advantages: 1. By precise sensor monitoring to distinguish between power failure and collision out-of-control two main failure modes, and start the corresponding multi-stage buffer recovery program, effectively solve the existing recovery system in high altitude buffer insufficient, low altitude deceleration invalid problem, at the same time multiple trigger conditions ensure that the system only responds when the real failure occurs, avoid the occurrence of misjudgment, make the system can adapt to the two different falling scene of high altitude and low altitude, significantly improve the recovery success rate and equipment safety; 2. Innovative structural design ensures the rapid, reliable deployment and efficient coordination of each buffer component: the bottom ring-shaped arrangement of the size combination airbag provides initial uniform buffer and anti-rollover ability; the top lift component cooperates with the memory metal skeleton to provide stable deceleration buoyancy; the symmetrical ejection parachute on both sides of the fuselage ensures the final balanced soft landing, these components and their rapid response mechanism together guarantee the stable operation of multi-stage buffer process in a very short time, maximize the buffer effect; 3. While realizing the high-low altitude compatible protection capability, the recovery system optimizes resource utilization through intelligent fault identification and precise timing control, activates specific components only when needed, avoids the redundancy and interference of all components starting at the same time; ensures that each buffer means can seamlessly connect and not interfere with each other in emergency, finally realizes the safe and controllable recovery of unmanned aerial vehicle under multiple failure modes. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 A flow chart of an unmanned aerial vehicle recovery system and control method based on multi-stage buffer is provided for the present application; Figure 2 An unmanned aerial vehicle shaft side view diagram of an unmanned aerial vehicle recovery system and control method based on multi-stage buffer is provided for the present application; Figure 3 An unmanned aerial vehicle bottom view diagram of an unmanned aerial vehicle recovery system and control method based on multi-stage buffer is provided for the present application; Figure 4 A schematic diagram of an airbag assembly in an unmanned aerial vehicle recovery system and control method based on multi-stage buffer is provided for the present application.

[0027] Explanation of reference numerals: 1, unmanned aerial vehicle; 2, airbag assembly; 21, first support; 22, first airbag; 23, first gas generating tank; 3, parachute assembly. DETAILED DESCRIPTION

[0028] The application provides a multi-level buffer-based unmanned aerial vehicle recovery system and control method, which is used to solve the technical problem that the existing unmanned aerial vehicle recovery system cannot meet the high-low altitude recovery requirements in the prior art.

[0029] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and cannot be used to limit the present application.

[0030] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0031] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the present application.

[0032] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If the first and the second are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0033] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0034] Example 1 As Figures 2 to 4The embodiment of the application shown provides a multi-stage buffer-based unmanned aerial vehicle recovery system, comprising an unmanned aerial vehicle 1, a main control system, a sensor system and a power supply system for supplying power to the unmanned aerial vehicle 1 are fixedly installed in the unmanned aerial vehicle 1; the power supply system comprises a main power supply and an emergency power supply; a gas bag assembly 2 is arranged at the bottom of the fuselage of the unmanned aerial vehicle 1; a lifting assembly is arranged at the top of the fuselage of the unmanned aerial vehicle 1; a plurality of parachute assemblies 3 are symmetrically arranged at the two sides of the fuselage of the unmanned aerial vehicle 1; the sensor system monitors the operating parameters of the unmanned aerial vehicle 1 and feeds back to the main control system, and the main control system receives the signals of the sensor system and controls the operation of the gas bag assembly 2, the lifting assembly and the parachute assembly 3.

[0035] More preferably, in the embodiment provided by the application, the unmanned aerial vehicle 1 is a 20 kg level plant protection unmanned aerial vehicle, the attitude sensor in the sensor system adopts “InvenSense MPU-9250”, is installed above the flight control mainboard of the unmanned aerial vehicle 1, and is used for collecting three-axis acceleration and angular velocity data; the current detection sensor adopts “ACS758LCB-050B”, is connected in series in the main loop of the power supply of the unmanned aerial vehicle 1 and is close to the battery end, and is used for detecting the current change rate; the air pressure sensor adopts “BMP280”, is installed at the ventilation hole of the side of the fuselage of the unmanned aerial vehicle 1, and is used for measuring the air pressure change to calculate the descent rate; the three sensors are all fixed with the mounting surface through shock-absorbing silica gel pads, the sensor cable adopts shielded twisted pair “AWG26”, and is fixed to the inner wall of the machine body through a metal clamp with a width of 5 mm to prevent vibration interference; the power supply system comprises the main power supply and the emergency power supply connected in parallel.

[0036] The six first gas bags 22 in the gas bag assembly 2 are rigidly connected with the bottom frame of the unmanned aerial vehicle 1 through high-strength lightweight alloy first supports 21, an electromagnetic lock catch is arranged on the first support 21, the electromagnetic lock catch is electrically connected with the main control system of the unmanned aerial vehicle 1, the electromagnetic lock catch is powered off during recovery, the first gas bag 22 in the flat compressed state is separated from the electromagnetic lock catch; a first gas generating tank 23, i.e. a “cylindrical sodium azide gas generating agent tank”, is integrally arranged at the inflation port of each first gas bag 22, the first gas generating tank 23 is fixed to the inner side wall of the gas bag through threads, and a heat-sensitive trigger type burst diaphragm is arranged between the first gas generating tank 23 and the inflation channel; as Figure 3 and Figure 4 As shown, the gas flow directions of the first gas generating tanks 23 in two adjacent first gas bags 22 are counterclockwise, the gas flow directions of the first gas generating tanks 23 in the other four first gas bags 22 are clockwise, the gyroscopic effect is generated through the asymmetric air flow design to realize the self-stabilization of the unmanned aerial vehicle 1, and the side turning is avoided.

[0037] The volume of the second air bag is 0.3 m³, and the material is 20D nylon silicon-coated fabric; the volume of the third air bag is 0.2 m³, and the material is aluminum-plated polyester film; the second air bag and the third air bag are combined into one through heat fusion welding of a width of 20 mm air-tight connecting belt; the connecting belt is fixed on the carbon fiber second bracket with a top section of 10 mm x 10 mm on the top of the unmanned aerial vehicle 1 through a Kevlar fiber rope with a diameter of 2 mm; the bracket bottom is provided with a skeleton made of memory metal such as "Ni-Ti alloy"; in the initial state, the skeleton is folded in Z shape, and the second air bag and the third air bag are folded into a cube with a size of 100 mm x 100 mm x 50 mm; after receiving the command trigger, the skeleton is heated to 60°C through the integrated second heating wire, and restored to a straight line shape, pushing the second bracket away from the top of the unmanned aerial vehicle 1, while the second air bag and the third air bag are inflated and unfolded.

[0038] As shown in Figure 2 two groups of micro parachute assemblies 3 are installed on the left and right sides of the unmanned aerial vehicle 1, respectively; each parachute cabin is provided with a hinged cabin door driven to open by a micro servo drive motor; the parachute cabin is provided with a parachute bag driven by an ejection plate; the canopy in the parachute bag is woven with ultra-high molecular weight polyethylene fiber with a diameter of 200 mm; the parachute rope is a seven-strand Kevlar fiber with a diameter of 0.5 mm; a pre-tension spring is arranged in the parachute bag; when the parachute is opened, the spring is ejected to pull the parachute rope, so that the canopy is completely unfolded within 0.3 s, and the impact load is ≤5G.

[0039] In the embodiment, by providing a multi-stage buffer recovery system composed of a main control system, a sensor system, a power supply system, an air bag assembly 2, a lifting assembly and a parachute assembly 3 on the unmanned aerial vehicle 1, the main control system determines the data monitored by the sensor system to automatically determine the high and low air faults of the unmanned aerial vehicle 1 and run the corresponding recovery program, effectively solving the problem that the existing recovery system cannot simultaneously meet the high and low air recovery requirements; at the same time, through the coordinated control of the main control system, the orderly operation of each component is realized, the timing conflict is avoided, and the safe recovery of the unmanned aerial vehicle 1 in the case of power failure or collision out of control is ensured.

[0040] Embodiment 2 As shown in Figure 1 the embodiment of the present application provides a control method of a multi-stage buffer-based unmanned aerial vehicle recovery system, comprising the following specific steps: S1, the sensor system monitors the running state of the unmanned aerial vehicle 1 and transmits the monitoring data to the main control system; when the main control system monitors that the running state of the unmanned aerial vehicle 1 is abnormal, step S2 is entered; S2, the main control system judges the abnormal state of the unmanned aerial vehicle 1, if the sensor system monitors that the main power voltage is lower than the preset voltage value, and the sensor system monitors that the vertical acceleration of the unmanned aerial vehicle 1 is greater than the first preset acceleration, the emergency power is activated to enter the early warning program, if the sensor system monitors that the vertical acceleration is greater than the second preset acceleration within the first preset time period after the early warning program is started, it is judged that the power failure abnormality; if the sensor system monitors the lateral acceleration, it is judged that the collision out-of-control abnormality; S3, according to the determination result of step S2, the corresponding program is executed, if it is power failure abnormality, the main control system executes power failure recovery program, when the sensor system monitors that the vertical acceleration is greater than the third preset acceleration within the second preset time period, first, the main control system sends a signal to make the air bag assembly 2 arranged at the bottom of the unmanned aerial vehicle 1 body inflate and deploy to buffer, then the main control system sends a signal to make the lift assembly arranged at the top of the unmanned aerial vehicle 1 body inflate and deploy and heat, when the sensor system monitors that the height is stable, the main control system sends a signal to make the air release valve in the lift assembly start, at the same time, the main control system sends a signal to make the plurality of parachute assemblies 3 arranged on both sides of the unmanned aerial vehicle 1 body pop up and deploy; if it is collision out-of-control abnormality, the main control system executes collision out-of-control recovery program, the main control system sends a signal to make the air bag assembly 2 at the bottom of the unmanned aerial vehicle 1 body inflate and deploy, at the same time, the main control system sends a signal to make the plurality of parachute assemblies 3 pop up and deploy.

[0041] More preferably, in the embodiments provided in the application, the rated voltage of the main power supply is 12V, the preset voltage value in the recovery system is 60% of the rated voltage of the main power supply, that is, 7.2V, the first preset acceleration is 3m / s², the second preset acceleration is 5m / s², the third preset acceleration is 8m / s², the first preset time period is 200ms, and the second preset time period is 300ms.

[0042] In this embodiment, if the internal power supply of the unmanned aerial vehicle 1 suddenly fails and the voltage drops to 5V, which is lower than the preset voltage value 7.2V, when the unmanned aerial vehicle 1 is working at a height of about 50 meters, the current detection sensor in the internal sensor system of the unmanned aerial vehicle 1 immediately captures this abnormal current change, and the attitude sensor monitors that the vertical acceleration instantaneously increases to 4.2m / s² due to the loss of the power part of the unmanned aerial vehicle 1. According to the preset condition that the main power voltage suddenly drops below the preset voltage value and the vertical acceleration is greater than the first preset acceleration 3m / s², the main control system immediately activates the emergency backup power supply to maintain the core system operation, and the attitude sensor continuously feeds back the vertical acceleration data. Since the unmanned aerial vehicle 1 starts to lose speed and descend, the acceleration continues to rise, when the attitude sensor continuously monitors that the vertical acceleration of the unmanned aerial vehicle 1 is greater than 5m / s² within 200ms, the main control system in step S2 judges that the power fails accordingly, and enters the power failure recovery program.

[0043] After entering the power failure recovery program in step S3, the unmanned aerial vehicle 1 continues to descend, and when the attitude sensor continuously monitors that the vertical acceleration of the unmanned aerial vehicle 1 is greater than 8 m / s2 within 300 ms, the main control system immediately sends a command to the airbag assembly 2 located at the bottom of the fuselage, the electromagnetic lock on the first support 21 of the airbag assembly 2 is instantaneously powered off to release the magnetic attraction force, the six compressed first airbags 22 are separated from the bottom of the unmanned aerial vehicle 1, and the electric heating wire in the first gas generator 23 is instantaneously powered on to generate high temperature to ignite sodium azide, which decomposes to generate nitrogen gas within 50 ms, the gas rushes into the airbag through the 8 mm diameter inflation channel, the diaphragm burst pressure is set to 0.5 MPa, ensuring that the gas fills the 0.5 m3 first airbag 22 within 80 ms, the high-pressure gas rapidly fills the airbag, and the annular array of airbags is inflated and deployed within milliseconds, wrapping the bottom of the unmanned aerial vehicle 1 to form a 1.2 m diameter buffer platform, continuously generating an upward impact force, and the unmanned aerial vehicle 1 preliminarily slows down.

[0044] At the same time, the skeleton is heated to 60°C to restore its linear shape, and after the airbag assembly 2 is deployed, the second and third airbags are inflated within 2 s, providing buoyancy, and the first electric heating wire in the third airbag heats the gas in the third airbag to increase its temperature by 20°C, causing the unmanned aerial vehicle 1 to slowly rise at a speed of 0.5 m / s and enter a hovering state.

[0045] When the air pressure sensor detects that the height is stable, the air release valve on the second airbag is started to release air at a rate of 5 L / s, and the two parachute assemblies 3 are ejected with a parachute at a gas pressure of 0.1 MPa, finally ensuring that the unmanned aerial vehicle 1 lands smoothly at a speed of 1.2 m / s.

[0046] In this embodiment, if the unmanned aerial vehicle 1 accidentally collides while spraying pesticide at an altitude of 5 meters, the sensor system first monitors a strong lateral acceleration impact in step S1, at which time the main control system directly determines a collision out of control in step S2, enters the collision out of control recovery program in step S3, and immediately triggers the inflation and deployment of the bottom airbag assembly 2 and the ejection and deployment of the two side parachute assemblies 3, omitting the lift assembly step, to respond to the emergency situation of near-earth falling at the fastest speed.

[0047] In the embodiment, the flight state is monitored in real time by the sensor system and the monitoring data is transmitted to the master control system, the master control system determines two main failure modes of power failure and collision out of control according to the monitoring data, and triggers the corresponding multi-stage buffer recovery program, effectively solving the problem that the existing recovery system cannot meet the high and low altitude recovery requirements; in the case of power failure, first, the bottom airbag assembly 2 is used for buffering, then the top lift assembly is unfolded and heated to provide buoyancy, and finally the parachute is released to achieve soft landing when the height is stable, through the multi-stage time sequence cooperative design of the airbag assembly 2, the lift assembly and the parachute assembly 3, both the long distance deceleration requirement of high altitude falling and the rapid start of airbag assembly 2 and parachute assembly 3 for joint buffering in low altitude collision can be met, which significantly improves the recovery success rate at different heights, and through the preset acceleration threshold and preset time period determination, the system conflict and resource waste caused by false touch are effectively avoided.

[0048] It should be noted that the above-mentioned sequence of the embodiments of the application is only for description, and does not represent the advantages and disadvantages of the embodiments. And the above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve the desired result. In addition, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are possible or advantageous.

[0049] The above only describes the preferred embodiments of the application and does not limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

[0050] The present application is only an exemplary description of the present application, and should be considered to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the present application and its equivalents, the present application is intended to include these modifications and variations.

Claims

1. A drone recovery system based on multi-level buffering, characterized in that: The system includes a drone (1), which has a main control system, a sensor system and a power supply system for powering the drone (1) fixedly installed inside; the power supply system includes a main power supply and an emergency power supply; the drone (1) has an airbag assembly (2) at the bottom of its fuselage; the drone (1) has a lift assembly at the top of its fuselage; and multiple parachute assemblies (3) are symmetrically arranged on both sides of the drone (1); the sensor system monitors the operating parameters of the drone (1) and feeds them back to the main control system, and the main control system receives the signals from the sensor system and controls the operation of the airbag assembly (2), the lift assembly and the parachute assembly (3).

2. The UAV recovery system based on multi-level buffering according to claim 1, characterized in that, The sensor system includes an attitude sensor for monitoring acceleration, a current monitoring sensor for monitoring current changes, and a barometric pressure sensor for monitoring descent rate. The attitude sensor is located inside the fuselage of the UAV (1), the current monitoring sensor is located in the power circuit inside the UAV (1), and the barometric pressure sensor is located at a ventilation hole on one side of the fuselage of the UAV (1).

3. The UAV recovery system based on multi-level buffering according to claim 1, characterized in that, The airbag assembly (2) includes a first support (21) and six compressed first airbags (22). The first support (21) is located at the bottom of the fuselage of the drone (1). The six compressed first airbags (22) are connected in a ring and arranged around the bottom of the fuselage of the drone (1). Each first airbag (22) is connected to the first support (21). Each compressed first airbag (22) has a first gas generator (23) at its inflation port for rapid inflation and deployment.

4. The UAV recovery system based on multi-level buffering according to claim 3, characterized in that, The six first airbags (22) are connected end to end by a magnetic quick-release interface. The inflation ports of two adjacent first airbags (22) are located at the first end, and the inflation ports of the other four first airbags (22) are located at the tail end.

5. The UAV recovery system based on multi-level buffering according to claim 1, characterized in that, The lifting assembly includes a connecting belt, a second airbag, and a third airbag. The connecting belt connects the second and third airbags. The second airbag contains a second gas generator for filling with helium or hydrogen. The third airbag contains a third gas generator for rapid inflation. The third airbag contains a first heating wire for heating the gas. The first heating wire is electrically connected to the main control system and the power supply system. The second airbag has a vent valve that is connected to the main control system for signal transmission.

6. The UAV recovery system based on multi-level buffering according to claim 5, characterized in that, The lifting component also includes a second bracket and a frame made of shape memory metal. One end of the frame is connected to the top of the fuselage of the UAV (1), and the other end of the frame is connected to the second bracket. The connecting strap is connected to the second bracket, and the second airbag in a compressed state and the third airbag in a compressed state are fixed on the second bracket. The frame is folded in a "Z" shape, and a second heating wire electrically connected to the main control system is integrated on the frame.

7. The UAV recovery system based on multi-level buffering according to claim 1, characterized in that, The UAV (1) has two parachute assemblies (3) symmetrically arranged on both sides of its fuselage. Each parachute assembly (3) includes a parachute compartment and a parachute pack. The upper surface of the parachute compartment is provided with a hinged door. Each door is controlled by a drive motor electrically connected to the main control system. Each parachute pack is located inside the parachute compartment. Each parachute compartment is provided with an ejection plate for ejecting the parachute pack.

8. A control method for a UAV recovery system based on multi-level buffering, characterized in that, The drone recovery system according to any one of claims 1-7 includes the following specific steps: S1. The sensor system monitors the operating status of the UAV (1) and transmits the monitoring data to the main control system. When the main control system detects that the UAV's operating status is abnormal, it proceeds to step S2. S2. The main control system judges the abnormal operating state of the UAV. If the sensor system detects that the main power supply voltage is lower than the preset voltage value and the sensor system detects that the vertical acceleration of the UAV (1) is greater than the first preset acceleration, the emergency power supply is activated to enter the warning program. If the sensor system detects that the vertical acceleration is greater than the second preset acceleration within the first preset time period after the warning program is started, it is determined to be an abnormal power failure. If the sensor system detects lateral acceleration, it determines that the collision is out of control. S3. Execute the corresponding program according to the judgment result of step S2. If it is a power failure abnormality, the main control system executes the power failure recovery program. When the sensor system detects that the vertical acceleration is greater than the third preset acceleration in the second pre-launch time period, the main control system first sends a signal to inflate and deploy the airbag assembly (2) located at the bottom of the UAV (1) fuselage for buffering. Then, the main control system sends a signal to inflate and deploy the lift assembly located at the top of the UAV (1) fuselage and heat it. When the sensor system detects that the altitude is stable, the main control system sends a signal to activate the deflation valve in the lift assembly. At the same time, the main control system sends a signal to pop out and deploy the multiple parachute assemblies (3) located on both sides of the UAV (1) fuselage. If the collision loss of control is abnormal, the main control system executes the collision loss of control recovery procedure. The main control system sends a signal to inflate and deploy the airbag assembly (2) at the bottom of the UAV (1) fuselage. At the same time, the main control system sends a signal to deploy multiple parachute assemblies (3).

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