CN110775287B

CN110775287B - Multi-rotor unmanned aerial vehicle emergency crash ejection type protection device

Info

Publication number: CN110775287B
Application number: CN201911118072.5A
Authority: CN
Inventors: 陈延礼; 彭淦; 李继财; 程延耕; 秦靖淳; 商艺琢; 施宇; 罗松松
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2020-12-25
Anticipated expiration: 2039-11-15
Also published as: CN110775287A

Abstract

The utility model provides a many rotor unmanned aerial vehicle promptly crash and launch formula protection device belongs to unmanned aerial vehicle protection technical field, and aim at solves the no crash protection device that prior art exists and leads to unmanned aerial vehicle to take place the big problem of economic loss after the crash. The invention comprises an ejection part and n groups of recoil parts; the ejection section includes: one end of the ejection sliding cylinder is fixed on the multi-rotor unmanned aerial vehicle through a fixed ring seat; the rudder unit is fixed on the fixed ring seat; the ejector is arranged in the ejection sliding cylinder and is controlled and limited by a steering engine set to eject at one end of the ejection sliding cylinder close to the fixed ring seat or at the other end; the speed reducing device is arranged on the ejector and is driven by the ejector to retract or eject the ejection sliding barrel; each group of recoil parts comprises two pairs of recoil structures symmetrically arranged on two rotors of the multi-rotor unmanned aerial vehicle, each pair of recoil structures comprises two oppositely-arranged traction legs arranged on one rotor, and each traction leg is provided with a recoil device.

Description

Multi-rotor unmanned aerial vehicle emergency crash ejection type protection device

Technical Field

The invention belongs to the technical field of unmanned aerial vehicle protection, and particularly relates to an emergent crash ejection type protection device for a multi-rotor unmanned aerial vehicle.

Background

Multi-rotor unmanned aerial vehicle is a special unmanned rotor aircraft with three and more rotor shafts, and it drives the rotor through every epaxial motor rotation of controller control to produce the lift. The collective pitch of the rotors is fixed and not variable as in a typical helicopter. The single-shaft propelling force can be changed by changing the relative rotating speed between different rotors, so that the running track of the aircraft is controlled; the GPS height position indicator, the air pressure height measurement auxiliary plate, the gyroscope and the sound wave distance measuring instrument module which are carried on the electronic equipment cabin of the multi-rotor unmanned aerial vehicle can acquire corresponding data, and the controller of the multi-rotor unmanned aerial vehicle can sense the flight attitude and the distance from the ground.

In the navigation of a multi-rotor unmanned aerial vehicle, the following situations can cause crash:

1. the power such as battery power-off, power-off cuts off, loses the problem lost. The unmanned aerial vehicle is unstable in voltage, the battery is not fully charged, the electric quantity is rapidly lost during flight, the voltage suddenly drops, the motor stalling rotating speed is reduced due to sudden power failure, and the unmanned aerial vehicle is rapidly reduced in height and crashed. Many rotor unmanned aerial vehicle's flight power is provided by the motor, and lack one can not to have the redundancy design. If the motor of one of them axle is malfunctioning to block commentaries on classics, or power transmission disappears suddenly etc. and leads to the flight state to appear unusual heeling, the flight performance of unmanned aerial vehicle can very big influence in these circumstances, leads to falling the fryer.

2. The positioning system fails. Unmanned aerial vehicle relies on the GPS signal to fix a position, and the operation picture can show unmanned aerial vehicle and receive the figure of satellite signal. If there are hillock separation, building or overhead electric tower interference, GPS signal loss during the flight, can appear hovering unstably, the automatic failure of returning a journey, unmanned aerial vehicle at this moment often can't accept command speed reduction, command mistake, can't switch the condition of manual mode operation, can't steadily descend immediately. Satellite signal reception can be disturbed by different external factors, and prevention is quite difficult, so that accidents are very easy to happen and crash is caused.

3. Over-the-horizon flight, errors in guidance, lost pictures, operator errors, and other accidents. If display and operating system crash in flight, then unmanned aerial vehicle will be difficult to confirm which direction is the principal point, judges the mistake easily, leads to the unmanned aerial vehicle crash. When the unmanned aerial vehicle flies, if the compass makes a mistake, the unmanned aerial vehicle still flies normally in the last second, and then flies and rotates disorderly in the next second. The electronic device is difficult to stably hover, always deviates to one side, and even if the electronic device is stopped, the electronic device cannot stop, and the electronic device is rotated, and other action errors cause crash.

Because unmanned aerial vehicle cost is very high, in case take place the crash, the unmanned aerial vehicle organism can lead to the fact the damage of different degrees, so, the economic loss that the unmanned aerial vehicle crash caused is very big, does not have the protection device to the unmanned aerial vehicle crash at present.

Disclosure of Invention

The invention aims to provide an emergent crash ejection type protection device for a multi-rotor unmanned aerial vehicle, and solves the problem that the unmanned aerial vehicle has large economic loss after being crashed due to the fact that no crash protection device exists in the prior art.

In order to achieve the purpose, the ejection type protection device for the emergency crash of the multi-rotor unmanned aerial vehicle comprises an ejection part and n groups of recoil parts;

the ejection section includes:

one end of the ejection sliding cylinder is fixed on the multi-rotor unmanned aerial vehicle through a fixed ring seat;

the rudder unit is fixed on the fixed ring seat;

the ejector is arranged in the ejection sliding cylinder and is controlled and limited by a steering engine set to eject at one end of the ejection sliding cylinder close to the fixed ring seat or at the other end;

the speed reducing device is arranged on the ejector and is driven by the ejector to retract or eject the ejection sliding barrel;

each group of recoil parts comprises two pairs of recoil structures symmetrically arranged on two rotors of the multi-rotor unmanned aerial vehicle, each pair of recoil structures comprises two oppositely-arranged traction legs arranged on one rotor, and each traction leg is provided with a recoil device.

The ejector includes:

the ejection sliding barrel is matched with the ejection sliding barrel in a sliding mode, and the speed reducing device is installed on the ejection main body;

and the ejection damping structure is arranged between the ejection main body and the ejection sliding cylinder, and the ejection main body is positioned at one end of the ejection sliding cylinder close to the fixed ring seat or ejected towards the other end by limiting or releasing the ejection damping structure through the rudder unit.

The ejection main body is in sliding fit with the ejection sliding barrel and specifically comprises the following steps: a plurality of sliding rollers are uniformly distributed on the circumference of the outer surface of the ejection main body, and the sliding rollers are in sliding fit with the inner wall of the ejection sliding barrel.

The ejection damping structure includes:

one end of a large damping spring arranged in the ejection sliding barrel is contacted with one end of the ejection sliding barrel close to the fixed ring seat, and the other end of the large damping spring is sleeved on a mounting table extending out of the end part of the ejection main body and is contacted with a shaft shoulder;

a plurality of barbs are uniformly distributed on the outer circumference of the ejection main body;

and the high-elastic rubber band is connected with the barb and one end of the ejection sliding cylinder, which is far away from the fixed ring seat.

A plurality of vertical sliding chutes arranged along the axis direction are uniformly distributed on the circumference of the cylinder wall of the ejection sliding cylinder, and two horizontal sliding chutes are symmetrically arranged on the cylinder wall of one end, close to the fixed ring seat, of the ejection sliding cylinder and are positioned around the center of the circle of the section where the ejection sliding cylinder is positioned; the barbs respectively extend out of the vertical sliding grooves and are in sliding fit with the vertical sliding grooves; the steering engine set drives the two limiting arms which are symmetrically arranged to be screwed in or screwed out from the two horizontal sliding grooves relative to the ejection sliding barrel, when the limiting arms are screwed in the ejection sliding barrel, the limiting arms and the ejection main body ejection motion front end contact and limit the ejection main body to be located at one end, close to the fixed ring seat, of the ejection sliding barrel, and when the limiting arms are screwed out of the ejection sliding barrel, the ejection main body is released.

Launch the part still including fixed connection in launch the damping lid that slides the section of thick bamboo other end, the damping is covered outer circumference equipartition a plurality of and is launched the parallel damping hole of a section of thick bamboo axis, and is a plurality of damping hole and a plurality of vertical spout one-to-one, every the one end of barb and a high-elastic rubber band is connected, the other end of high-elastic rubber band and the damping jogged joint that corresponds.

The fixed ring seat comprises a fixed main body and an auxiliary fixed part which are matched in a screw fastening mode through a threaded hole, the hole wall of the fixed main body is in interference fit with and fastened to the outer wall of the ejection sliding barrel, and the lower end face of the fixed main body is located on a step at the bottom of the ejection sliding barrel and is limited.

The speed reduction device is a small parachute or a high-altitude speed reduction air bag, and the small parachute or the high-altitude speed reduction air bag is connected with the traction leg of the recoil part through a traction rope.

The traction leg part is provided with a buffer hole and a trigger hole which are crossed and communicated in a crossed manner; the recoil device comprises a recoil high-pressure air bag which is arranged in the buffer hole and is used for rushing high-pressure gas and a trigger which is arranged in the trigger hole.

The invention has the beneficial effects that: the rudder unit, the catapult sliding cylinder and the damping cover of the catapult type protection device for the emergency crash of the multi-rotor unmanned aerial vehicle are assembled into a whole, and the fixed ring seat is installed and fastened on the top or the side of the multi-rotor unmanned aerial vehicle through screws. The traction legs can be grouped and fixed on the motor rotor arm by screws or nylon bands and the like. Parachute or high altitude air bag decelerator pull unmanned aerial vehicle's rope line spacing and pull between the shank group and relatively install fixedly. The distances between the traction leg groups and the main body are equal, so that the unmanned plane can descend in the air at a stable posture in a deceleration way. The recoil device is arranged in the traction leg part and is exploded by the trigger to generate recoil force. The acting force which is possibly left after the unmanned aerial vehicle decelerates in the air and is generated by collision with the ground is reduced, and the damage to the unmanned aerial vehicle is relieved again. The control lines of the rudder unit and the recoil device are connected with the controller, and the execution signal is sent by the controller.

Six-degree-of-freedom data including the height of the unmanned aerial vehicle are sensed in real time through the GPS height positioning and the air pressure height measurement auxiliary plate in combination with the gyroscope and are transmitted to the controller. When the sensed flight attitude triggers a safety boundary angle, or the data change value and the speed of the height and the degree of freedom exceed a certain threshold value, the flight control sends a signal to a motor set of the multi-rotor unmanned aerial vehicle to stop the motor set, then sends the signal to a steering unit to enable a limiting arm of the steering unit to remove the limitation on the ejector, the ejector ejects a parachute or other high-altitude deceleration airbags inversely arranged in the ejection sliding cylinder, and the unmanned aerial vehicle decelerates and falls from high altitude. When the sound wave distancer module measured distance ground reached the threshold value, the controller sent signal for recoil ware, recoil ware recoil unmanned aerial vehicle reduces many rotor unmanned aerial vehicle falling speed and downbearing force once more, avoids the rigidity of a wide margin offend of many rotor unmanned aerial vehicle and ground, reduces the damage degree when many rotor unmanned aerial vehicle crashed, and then reduces the economic loss that the crash brought.

Drawings

Fig. 1 is a schematic view of the overall structure of an emergency crash ejection type protection device for a multi-rotor unmanned aerial vehicle according to the invention;

fig. 2 is a schematic structural view of an ejection part in the multi-rotor unmanned aerial vehicle emergency crash ejection type protection device of the invention;

fig. 3 is a structural cross-sectional view of an ejection part in the multi-rotor unmanned aerial vehicle emergency crash ejection type protection device of the invention;

fig. 4 is a partial cross-sectional view of a traction leg structure in an emergency crash ejection type protection device for a multi-rotor unmanned aerial vehicle according to the present invention;

fig. 5 is a schematic view of the installation of an emergency crash ejection type protection device for a multi-rotor unmanned aerial vehicle on the top of the multi-rotor unmanned aerial vehicle according to the present invention;

fig. 6 is a schematic view of the installation of the emergency crash ejection type protection device for a multi-rotor unmanned aerial vehicle on the side surface of the multi-rotor unmanned aerial vehicle, according to the present invention;

wherein: 1. the ejection part is used for ejecting the liquid,

11. a fixing ring seat 111, a fixing body 112, an auxiliary fixing part,

12. an ejection sliding cylinder 121, a vertical chute 122 and a horizontal chute,

13. a rudder unit, 131, a limit arm,

14. ejector 141, ejection body 142, sliding roller 143, large damping spring 144, barb 145, high elastic rubber band,

15. a damping cover 151, a damping hole,

2. a back-flushing part which is arranged on the back-flushing part,

21. traction legs, 211, buffer holes, 212, trigger holes,

22. a recoil device 221, a recoil high-pressure air bag 222 and a trigger.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings.

The invention adopts the ejection device to eject the parachute or other high-altitude deceleration airbags to greatly reduce the falling speed of the unmanned aerial vehicle in the air, and reduces the possible damage of the multi-rotor unmanned aerial vehicle when the multi-rotor unmanned aerial vehicle is in emergency crash by combining the mode of combining the recoil device 22 with the small-amplitude recoil deceleration near the ground, thereby having safe use. Under the conditions of expanding the ejection device and the recoil device and replacing recoil gas, higher dropping height and better falling protection effect can be achieved. The parts of the ejection device and the recoil device can be made of light metal such as aluminum alloy, and the ejection device and the recoil device are simple in machining and good in economical efficiency. The general large damping spring 143 and the high-elastic rubber band 145 can be flexibly selected to determine the sensitivity of the device.

Referring to the attached drawings 1-4, the catapult-type protection device for the emergency crash of the multi-rotor unmanned aerial vehicle comprises a catapult part 1 and n groups of recoil parts 2;

the ejector part 1 includes:

an ejection sliding cylinder 12, one end of which is fixed on the multi-rotor unmanned aerial vehicle through a fixed ring seat 11 and is vertical to the plane where the rotors are located;

the rudder unit 13 is fixedly connected to the fixed ring seat 11 through threads;

the ejector 14 is arranged in the ejection sliding cylinder 12, and the ejector 14 is controlled and limited in the ejection sliding cylinder 12 through a rudder unit 13 and is ejected at one end close to the fixed ring seat 11 or towards the other end;

and a speed reducer mounted on the ejector 14, wherein the speed reducer is driven by the ejector 14 to retract or eject the ejection sliding barrel 12;

each group of recoil parts 2 comprises two pairs of recoil structures symmetrically arranged on two rotors of the multi-rotor unmanned aerial vehicle, each pair of recoil structures comprises two oppositely-arranged traction leg parts 21 arranged on one rotor, and each traction leg part 21 is provided with a recoil device 22. In the embodiment, two groups of recoil parts 2 are selected, screws penetrate through four threaded holes on the recoil parts and threaded holes in the same position on the other part, and the recoil parts can be fixed on the rotor arm by screwing the screws.

The ejector 14 includes:

the ejection body 141 is matched with the ejection sliding barrel 12 in a sliding mode, and the speed reducing device is installed on the ejection body 141;

and an ejection damping structure arranged between the ejection body 141 and the ejection sliding barrel 12, wherein the ejection body 141 is positioned at one end of the ejection sliding barrel 12 close to the fixed ring seat 11 or is ejected to the other end by limiting or releasing the ejection damping structure through the rudder unit 13.

The sliding fit of the ejection body 141 relative to the ejection sliding barrel 12 is specifically as follows: a plurality of sliding rollers 142 are uniformly distributed on the circumference of the outer surface of the ejection main body 141, and the sliding rollers 142 are in sliding fit with the inner wall of the ejection sliding barrel 12.

The ejection damping structure includes:

the large damping spring 143 is arranged in the ejection sliding barrel 12, the resilience force generated by the large damping spring 143 is larger than the self weight of the ejection protection device, the rebound stroke is larger than the height of the ejection sliding barrel 12, one end of the large damping spring is contacted with one end of the ejection sliding barrel 12 close to the fixed ring seat 11, and the other end of the large damping spring is sleeved on a mounting table extending out of the end part of the ejection main body 141 and is contacted with a shaft shoulder;

a plurality of barbs 144 circumferentially and uniformly distributed on the outer circumference of the ejection body 141; four barbs 144 are selected in this embodiment;

and a high-elasticity rubber band 145 which is connected with the barb 144 and one end of the ejection sliding cylinder 12 far away from the fixed ring seat 11, is used for assisting resilience, and has a large enough elasticity coefficient to provide tension to tighten the rubber band.

A plurality of vertical sliding chutes 121 arranged along the axial direction are uniformly distributed on the circumference of the cylinder wall of the ejection sliding cylinder 12, the number of the vertical sliding chutes 121 is four in this embodiment, and two horizontal sliding chutes 122 are symmetrically arranged on the cylinder wall of one end of the ejection sliding cylinder 12 close to the fixed ring seat 11 about the center of the circle of the section where the ejection sliding cylinder is located; the four barbs 144 respectively extend from the four vertical sliding grooves 121 and are in sliding fit with the vertical sliding grooves 121; the rudder unit 13 drives the two symmetrically arranged limiting arms 131 to rotate in or out from the two horizontal sliding grooves 122 relative to the ejection sliding barrel 12, when the limiting arms 131 rotate in the ejection sliding barrel 12, the limiting arms 131 and the ejection main body 141 are in contact with the front end of the ejection motion to limit the ejection main body 141 to be located at one end of the ejection sliding barrel 12 close to the fixed ring seat 11, and when the limiting arms 131 rotate out of the ejection sliding barrel 12, the ejection main body 141 is released.

Launch part 1 and still include fixed connection in launch the damping lid 15 that slides a 12 other end, the damping lid 15 goes up a plurality of damping holes 151 that slide a 12 axis parallel with launching of outer circumference equipartition, and the quantity of damping hole 151 is four in this embodiment, four damping hole 151 and four vertical spout 121 one-to-one, every barb 144 and the one end of a high-elastic rubber band 145 are connected, the other end of high-elastic rubber band 145 and the damping hole 151 that corresponds are connected. The high elastic rubber band 145 is arranged to increase the ejection force of the ejector 14 and the initial speed and acceleration force after the ejector is released, so as to completely decelerate the ejection of the ejector sliding barrel 12.

The fixing ring seat 11 comprises a fixing main body 111 and an auxiliary fixing part 112 which are connected through threaded holes in a threaded manner, the auxiliary fixing part 112 is provided with threaded holes for being conveniently connected with a rack when being fixed laterally, the hole wall of the fixing main body 111 and the outer wall of the ejection sliding barrel 12 are in interference fit and fastened, and the fixing main body 111 is located on a step at the bottom of the ejection sliding barrel 12 and is limited.

The speed reduction device is a small parachute or a high-altitude speed reduction air bag which is correspondingly configured according to different machine types and sizes, the small parachute or the high-altitude speed reduction air bag is arranged in the ejection sliding barrel 12 and automatically unfolded along with the dropping process of the unmanned aerial vehicle after ejection, the dropping resistance is increased so as to reduce the dropping speed, and the small parachute or the high-altitude speed reduction air bag is connected with the traction leg 21 of the recoil part 2 through a traction rope.

The traction leg part 21 is provided with a buffer hole 211 and a trigger hole 212 which are crossed and communicated in a cross way, the depth of the buffer hole is ensured to be in contact with the recoil high-pressure air bag, and the depth length of the trigger hole is ensured to be enough for placing the recoil high-pressure air bag; the recoil device 22 comprises a recoil high-pressure air bag 221 arranged in the buffer hole 211 and a trigger 222 arranged in the trigger hole 212, the size of the trigger 222 is ensured to be placed in the trigger hole, and the trigger 222 receives signals and releases electric pulses to puncture the recoil high-pressure air bag 221 so as to release high-pressure gas to generate recoil force for buffering and slowing down the falling speed. The number of groups of traction legs 21 is variable, and the number of rotor arms of the multi-rotor unmanned aerial vehicle can be flexibly adjusted.

The ejection part 1 of the application has the main executive component of the ejector 14, a large damping spring 143 is compressed in the ejection sliding barrel 12, and four barbs 144 on the upper outer part of the large damping spring are connected with a damping hole 151 formed in the upper end part of a damping cover 15 through a high-elastic rubber band 145; the small parachute or other high-altitude deceleration air bags are ejected by the large damping spring 143 and the high-elastic rubber band 145 together and accelerated along the sliding gap on the wall of the ejection sliding barrel 12. Install the 21 subtend connections of the shank of pulling on many rotor unmanned aerial vehicle's the rotor arm in groups, fixed small-size parachute or other high altitude air bags pull the rope that pulls the unmanned aerial vehicle body among the clearance. The recoil unit 22 built into the traction leg 21 is filled with a high-pressure compressed gas such as helium or the like. The control lines and the power lines of the steering unit 13 and the recoil device 22 are connected to the corresponding controllers and power interfaces.

Referring to fig. 5 and 6, the ejection in the protection device of the present invention can be installed on the upper part or the side of the main body of the multi-rotor unmanned aerial vehicle, depending on the structure and the size parameters of the multi-rotor unmanned aerial vehicle, so as not to affect the principle of flight. Six-degree-of-freedom data including height of the unmanned aerial vehicle are sensed in real time through the GPS height positioning and the air pressure height measurement auxiliary plate in combination with the gyroscope and are transmitted to the controller, when the controller senses that the flight attitude triggers a safety boundary angle or the change value and the speed of the height and the degree-of-freedom data exceed a threshold value, the ejector 14 is relieved from limitation by the limiting arm 131 of the steering engine group 13, the accelerated ejection process is realized in the ejection sliding cylinder 12, and the falling of the multi-rotor unmanned aerial vehicle is reduced. When the distance measured by the acoustic distance measuring instrument module reaches a threshold value from the ground, the recoil device 22 is triggered, the high-pressure gas is released downwards instantly, relative recoil force is formed relative to the ground, and the speed is reduced by a small degree again. The unmanned aerial vehicle that takes place to fall because emergency collides with the great amplitude rigidity on ground in avoiding follow the high altitude through twice speed reduction, protects unmanned aerial vehicle, reduces the harm that probably forms.

Claims

1. An emergent crash ejection type protection device for a multi-rotor unmanned aerial vehicle is characterized by comprising an ejection part (1) and n groups of recoil parts (2);

the ejection part (1) comprises:

one end of the ejection sliding cylinder (12) is fixed on the multi-rotor unmanned aerial vehicle through a fixed ring seat (11);

a rudder unit (13) fixed on the fixed ring seat (11);

the catapult (14) is arranged in the ejection sliding cylinder (12), and the catapult (14) is controlled and limited in the ejection sliding cylinder (12) through a rudder unit (13) to be near one end of the fixed ring seat (11) or catapult towards the other end;

and a speed reducer mounted on the ejector (14), wherein the speed reducer is driven by the ejector (14) to retract or eject the ejection sliding barrel (12);

each group of recoil parts (2) comprises two pairs of recoil structures symmetrically arranged on two rotors of the multi-rotor unmanned aerial vehicle, each pair of recoil structures comprises two oppositely arranged traction legs (21) arranged on one rotor, and each traction leg (21) is provided with a recoil device (22);

the ejector (14) comprises:

the ejection body (141) is matched with the ejection sliding barrel (12) in a sliding mode, and the speed reducing device is installed on the ejection body (141);

and the ejection damping structure is arranged between the ejection main body (141) and the ejection sliding barrel (12), and the ejection main body (141) is positioned at one end of the ejection sliding barrel (12) close to the fixed ring seat (11) or is ejected to the other end by limiting or releasing the ejection damping structure through the rudder unit (13).

2. The ejection type protection device for the emergency crash of a multi-rotor unmanned aerial vehicle according to claim 1, wherein the ejection body (141) is slidably fitted with respect to the ejection slide cylinder (12) by: a plurality of sliding rollers (142) are uniformly distributed on the circumference of the outer surface of the ejection main body (141), and the sliding rollers (142) are in sliding fit with the inner wall of the ejection sliding barrel (12).

3. The multi-rotor unmanned aerial vehicle emergency crash projectile protection device of claim 1, wherein said projectile damping structure comprises:

the large damping spring (143) is arranged in the ejection sliding barrel (12), one end of the large damping spring (143) is contacted with one end, close to the fixed ring seat (11), of the ejection sliding barrel (12), and the other end of the large damping spring is sleeved on a mounting table extending out of the end part of the ejection main body (141) and is contacted with a shaft shoulder;

a plurality of barbs (144) circumferentially and evenly distributed on the outer circumference of the ejection body (141);

and the high-elastic rubber band (145) is connected with the barb (144) and one end of the ejection sliding barrel (12) far away from the fixed ring seat (11).

4. The multi-rotor unmanned aerial vehicle emergency crash ejection type protection device is characterized in that a plurality of vertical sliding grooves (121) arranged along the axial direction are uniformly distributed on the circumference of the wall of the ejection sliding cylinder (12), and two horizontal sliding grooves (122) are symmetrically arranged on the wall of one end, close to the fixed ring seat (11), of the ejection sliding cylinder (12) and around the center of the circle of the section where the ejection sliding cylinder is located; the barbs (144) respectively extend out of the vertical sliding grooves (121) and are in sliding fit with the vertical sliding grooves (121); the rudder unit (13) drives the two limiting arms (131) which are symmetrically arranged to be screwed in or out from the two horizontal sliding grooves (122) relative to the ejection sliding barrel (12), when the limiting arms (131) are screwed in the ejection sliding barrel (12), the limiting arms (131) and the ejection main body (141) are in ejection motion front end contact with one ends of the ejection sliding barrel (12) close to the fixed ring seat (11) to limit the ejection main body (141), and when the limiting arms (131) are screwed out of the ejection sliding barrel (12), the ejection main body (141) is released.

5. The multi-rotor unmanned aerial vehicle emergency crash ejection type protection device according to claim 4, wherein the ejection part (1) further comprises a damping cover (15) fixedly connected to the other end of the ejection sliding cylinder (12), a plurality of damping holes (151) parallel to the axis of the ejection sliding cylinder (12) are uniformly distributed on the damping cover (15) along the outer circumference of the outer circumference, the damping holes (151) correspond to the vertical sliding grooves (121) in a one-to-one manner, each of the damping holes is connected to one end of the barb (144) and one end of the high-elastic rubber band (145), and the other end of the high-elastic rubber band (145) is connected to the corresponding damping hole (151).

6. The catapult-type protection device for the emergency crash of multi-rotor Unmanned Aerial Vehicle (UAV) according to claim 1, wherein the fixing ring seat (11) comprises a fixing body (111) and an auxiliary fixing part (112) which are connected through a threaded hole in a threaded manner, the hole wall of the fixing body (111) and the outer wall of the catapult sliding cylinder (12) are in interference fit and fastened, and the fixing body (111) is seated on the bottom step of the catapult sliding cylinder (12) and is limited.

7. The multi-rotor unmanned aerial vehicle emergency crash ejection protection device of claim 1, wherein the deceleration device is a small parachute or high altitude deceleration airbag connected to the traction leg (21) of the recoil part (2) by a traction rope.

8. An emergency crash ejection protection device for multi-rotor unmanned aerial vehicles according to any of claims 1-7, wherein the traction leg (21) is provided with a cross-through buffer hole (211) and a trigger hole (212); the recoil device (22) comprises a recoil high-pressure air bag (221) filled with high-pressure gas and arranged in the buffer hole (211) and a trigger (222) arranged in the trigger hole (212).