阅读说明：本技术 一种无人机复飞方法 (Unmanned aerial vehicle re-flying method ) 是由 岳焕印 廖小罕 叶虎平 于 2020-06-19 设计创作，主要内容包括：本发明涉及一种无人机复飞方法,当无人机在飞行时或/和当无人机在准备起飞返程时,若其旋翼发生损坏时,则通过电磁铁装置控制磁性弹片远离电机移动,使卡持电机的挂钩与电机完全脱离,并在弹簧的作用力下,使电机沿滑槽向下移动,在电机沿滑槽向下移动时,通过设置在折叠桨叶上的支撑件与旋翼相抵,使电机的转轴与旋翼完全分离,并在电机沿滑槽向下移动时,使折叠在连接件外侧的折叠桨叶连接在转轴上,并在离心力的作用下,使折叠桨叶展开,此时,折叠桨叶向无人机提供升力,以保证无人机能正常飞行或/和正常起飞,减少用户损失,且不会危及他人的生命安全。(The invention relates to a method for the follow-up flight of an unmanned aerial vehicle, which is characterized in that when the unmanned aerial vehicle flies or/and when the unmanned aerial vehicle is ready to take off and return, if the rotor wing of the unmanned aerial vehicle is damaged, the electromagnet device controls the magnetic elastic sheet to move away from the motor, so that the hook clamping the motor is completely separated from the motor, and the motor moves downwards along the sliding chute under the action of the spring, when the motor moves downwards along the sliding groove, the rotating shaft of the motor is completely separated from the rotor wing through the support piece arranged on the folding paddle to abut against the rotor wing, and when the motor moves downwards along the sliding chute, the folding paddle folded at the outer side of the connecting piece is connected on the rotating shaft, and under the action of centrifugal force, the folding blades are unfolded, at the moment, the folding blades provide lift force for the unmanned aerial vehicle, so as to ensure that the unmanned plane can normally fly or/and take off, reduce the loss of users and not endanger the life safety of other people.)

1. An unmanned aerial vehicle missed approach method is characterized by comprising the following steps:

when the rotor wing (3) is damaged, an instruction is sent to the electromagnet device (4) of the fly-back device, the magnetic elastic sheet (5) is controlled to move away from the motor (2), a hook (8) clamping the motor (2) is completely separated from the motor (2), and the motor (2) moves downwards along the sliding groove (6) under the action force of a spring (10);

when the motor (2) moves downwards along the sliding chute (6), a support piece (12) arranged on the folding blade is abutted against the rotor wing (3), so that a rotating shaft (11) of the motor (2) is completely separated from the rotor wing (3);

when the motor (2) moves downwards along the sliding chute (6), the folding paddle folded on the outer side of the connecting piece (1) is connected to the rotating shaft (11), and is unfolded under the action of centrifugal force;

wherein the re-flying device comprises the connecting piece (1), the motor (2), the rotor wing (3), the magnetic elastic sheet (5) and at least two folding blades, the bottom end of the connecting piece (1) is connected with the body of the unmanned aerial vehicle, a cylindrical sliding chute (6) is arranged in the connecting piece (1), a cover plate (7) used for covering the sliding chute (6) is arranged at the top end of the connecting piece (1), a first opening concentric with the axis of the sliding chute (6) is arranged on the cover plate (7), one end of the magnetic elastic sheet (5) is connected to the cover plate (7), the other end of the magnetic elastic sheet (5) is provided with a hook (8), the plurality of magnetic elastic sheets (5) are circumferentially arranged along the sliding chute (6), the plurality of electromagnet devices (4) are embedded in the connecting piece (1) and correspond to the plurality of magnetic elastic sheets (5) one by one, motor (2) bottom is equipped with along radially outwards protruding first ka tai (9), first ka tai (9) with be equipped with spring (10) that are in compression state between apron (7), it is a plurality of hook portion of couple (8) is located the below card of first ka tai (9) is held motor (2), just pivot (11) of motor (2) are worn out first opening and with rotor (3) are connected.

2. The method for unmanned aerial vehicle to fly back according to claim 1, wherein the device for flying back further comprises:

the folding blade comprises a fixed part (13) and a folding part (14) which is used for unfolding under the action of centrifugal force, the fixed part (13) is provided with the supporting part (12), and a 90-degree self-locking hinge piece (15) is arranged between the folding part (14) and the fixed part (13);

said unfolding of said folding blades under the effect of centrifugal force, comprising:

the folded portion (14) is unfolded by centrifugal force.

3. The method for unmanned aerial vehicle to fly back according to claim 2, wherein the device for flying back further comprises: a second clamping table (16) with a polygonal cross section is arranged on the rotating shaft (11), and a second opening matched with the second clamping table (16) is formed in the rotor wing (3);

the unmanned aerial vehicle missed approach method also includes: the motor (2) is followed before spout (6) downstream, right second ka tai (16) with the second opening carries out the joint, so that rotor (3) with pivot (11) carry out synchronous rotation.

4. An unmanned aerial vehicle missed approach flight device according to claim 3, wherein the missed approach flight device further comprises: the other end of the fixing part (13) is provided with a concave part matched with the second clamping table (16);

the connecting the folding blade folded outside the link (1) to the rotary shaft (11) when the motor (2) moves down along the sliding groove (6), comprising:

motor (2) are followed during spout (6) downstream, through right second ka tai (16) with the depressed part carries out the joint, will fixed part (13) are connected in pivot (11).

5. A method as claimed in claim 2 or 3, wherein the missed approach device further comprises: a bearing (17) concentric with the rotating shaft (11) is arranged at the top end of the motor (2), and a connecting rod (18) is arranged between the bearing (17) and the fixing part (13);

the unmanned aerial vehicle missed approach method also includes:

-fixing the fixing portion (13) by means of the connecting rod (18) before the motor (2) moves downwards along the chute (6);

and after the fixing part (13) is connected to the rotating shaft (11), the folding blade and the rotating shaft (11) synchronously rotate through the bearing (17).

6. An unmanned aerial vehicle missed approach method of any one of claims 1 to 4, characterized by further comprising:

acquiring the lift force of each rotor wing (3) of the unmanned aerial vehicle, judging the lift force of each rotor wing (3) and a preset lift force one by one, and determining whether the rotor wing (3) is damaged or not according to a comparison result; determining whether to issue the command to the electromagnet arrangement (4) according to the damage result.

Technical Field

The invention relates to the technical field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle missed-flight method.

Background

Along with the development of unmanned aerial vehicle technique, unmanned aerial vehicle can play more and more important effect in the middle of each field of each trade at home and abroad, and at present, unmanned aerial vehicle often can run into following problem, specifically:

1) when the unmanned aerial vehicle flies, if the rotor wing of the unmanned aerial vehicle is damaged, the unmanned aerial vehicle is often crashed, loss is caused to a user, and meanwhile, the life safety of people in the crash place is endangered;

2) when unmanned aerial vehicle lands and carries out the operation in a certain place and finishes, then when preparing to take off and return journey, if the rotor takes place to damage, make unmanned aerial vehicle can not normally take off to make unmanned aerial vehicle can not normally return, cause the loss for the user.

Disclosure of Invention

The invention provides a method for flying in a missed approach of an unmanned aerial vehicle, aiming at the defects of the prior art.

The technical scheme of the invention is as follows:

when the rotor wing is damaged, sending an instruction to an electromagnet device of the fly-back device, controlling the magnetic elastic sheet to move away from the motor, completely separating a hook clamping the motor from the motor, and enabling the motor to move downwards along the sliding groove under the action of a spring;

when the motor moves downwards along the sliding groove, a support piece arranged on the folding paddle is abutted against the rotor wing, so that the rotating shaft of the motor is completely separated from the rotor wing;

when the motor moves downwards along the sliding chute, the folding paddle folded at the outer side of the connecting piece is connected to the rotating shaft, and the folding paddle is unfolded under the action of centrifugal force;

wherein, the flyback device comprises the connecting piece, the motor, the rotor, the magnetic spring pieces and at least two folding blades, the bottom end of the connecting piece is connected with the body of the unmanned aerial vehicle, a cylindrical chute is arranged in the connecting piece, the top end of the connecting piece is provided with a cover plate for covering the chute, the cover plate is provided with a first opening concentric with the axle center of the chute, one end of the magnetic spring pieces is connected on the cover plate, the other end of the magnetic spring pieces is provided with a hook, a plurality of magnetic spring pieces are circumferentially arranged along the chute, a plurality of electromagnet devices are embedded in the connecting piece and correspond to the magnetic spring pieces one by one, the bottom end of the motor is provided with a first clamping table which is radially outwards convex, a spring in a compression state is arranged between the first clamping table and the cover plate, and the hook parts of the hooks are positioned below the first clamping table for clamping the motor, and the rotating shaft of the motor penetrates out of the first opening and is connected with the rotor wing.

The unmanned aerial vehicle re-flying method has the following beneficial effects:

when unmanned aerial vehicle when flight or/and when unmanned aerial vehicle is preparing to take off when returning, if when its rotor takes place to damage, then keep away from the motor through electromagnet device control magnetism shell fragment and remove, make the couple that the motor was held to the card break away from completely with the motor, and under the effort of spring, make the motor along spout downstream, when the motor along spout downstream, support piece through setting up on folding paddle offsets with the rotor, make the pivot and the rotor of motor separate completely, and when the motor along spout downstream, make folding the folding paddle in the connecting piece outside connect in the pivot, and under the effect of centrifugal force, make folding paddle expand, at this moment, folding paddle provides lift to unmanned aerial vehicle, in order to guarantee that unmanned aerial vehicle can normally fly or normally take off, reduce the user loss, and can not endanger other people's life safety.

On the basis of the scheme, the unmanned aerial vehicle missed approach method can be further improved as follows.

Further, the missed approach device further comprises: the folding paddle comprises a fixed part and a folding part which is used for unfolding under the action of centrifugal force, the supporting part is arranged on the fixed part, and a 90-degree self-locking hinge part is arranged between the folding part and the fixed part;

said unfolding of said folding blades under the effect of centrifugal force, comprising:

the folded portion is unfolded by centrifugal force.

The beneficial effect of adopting the further scheme is that: under the effect of centrifugal force, can expand the folded part completely through 90 degrees auto-lock articulated elements, make the folded part can not take place to rock to guarantee that unmanned aerial vehicle can steadily fly.

Further, the missed approach device further comprises: a second clamping table with a polygonal cross section is arranged on the rotating shaft, and a second opening matched with the second clamping table is formed in the rotor wing;

the unmanned aerial vehicle missed approach method also includes: the motor is followed before the spout removes downwards, right the second ka tai with the second opening carries out the joint, so that the rotor with the pivot carries out synchronous revolution.

The beneficial effect of adopting the further scheme is that: the motor is followed before the spout downstream, to the second card platform with the second opening carries out the joint, so that the rotor with the pivot carries out synchronous rotation.

Further, the missed approach device further comprises: the other end of the fixing part is provided with a concave part matched with the second clamping table;

when the motor moves downwards along the sliding groove, the folding paddle folded outside the connecting piece is connected to the rotating shaft, and the folding paddle folding device comprises:

the motor is followed when the spout removes downwards, through right the second card platform with the depressed part carries out the joint, will the fixed part is connected in the pivot.

The beneficial effect of adopting the further scheme is that: the motor is followed during spout downstream, through carrying out the joint to second card platform and depressed part, connect the fixed part in the pivot, guarantee that folding paddle can rotate along with the pivot of motor.

Further, the missed approach device further comprises: a bearing concentric with the rotating shaft is arranged at the top end of the motor, and a connecting rod is arranged between the bearing and the fixing part;

the unmanned aerial vehicle missed approach method also includes:

before the motor moves downwards along the sliding chute, fixing the fixing part through the connecting rod;

and after the fixing part is connected to the rotating shaft, the folding blades and the rotating shaft synchronously rotate through the bearing.

The beneficial effect of adopting the further scheme is that: before the motor moves downwards along the sliding chute, the fixing part is fixed through the connecting rod; the fixing part is connected behind the rotating shaft and is used for ensuring that the folding blades and the rotating shaft synchronously rotate through the bearing.

Further, still include:

acquiring the lift force of each rotor wing of the unmanned aerial vehicle, judging the lift force of each rotor wing one by one and a preset lift force, and determining whether the rotor wing is damaged or not according to a comparison result; and determining whether to send the command to the electromagnet device according to the damage result.

The beneficial effect of adopting the further scheme is that: by acquiring the lift force of each rotor wing of the unmanned aerial vehicle, judging the lift force of each rotor wing and the preset lift force one by one, and determining whether the rotor wing is damaged or not according to the comparison result; and determining whether to send an instruction to the electromagnet device according to the damage result, and is simple and convenient.

Drawings

Fig. 1 is a schematic flow chart of a method for missed approach of an unmanned aerial vehicle according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a missed approach device of an unmanned aerial vehicle;

FIG. 3 is a top view of the second boss coupled to the shaft and the rotor, respectively;

fig. 4 is a top view of the second boss being connected to the recess.

Detailed Description

As shown in fig. 1, an unmanned aerial vehicle missed approach method according to an embodiment of the present invention includes the following steps:

s1, when the rotor wing 3 is damaged, sending an instruction to the electromagnet device 4 of the fly-back device, controlling the magnetic elastic sheet 5 to move away from the motor 2, completely separating the hook 8 clamping the motor 2 from the motor 2, and enabling the motor 2 to move downwards along the chute 6 under the action of the spring 10;

s2, when the motor 2 moves downwards along the chute 6, the rotating shaft 11 of the motor 2 is completely separated from the rotor 3 by the support 12 arranged on the folding blade abutting against the rotor 3;

s3, when the motor 2 moves down along the chute 6, the folding blade folded outside the connector 1 is connected to the rotating shaft 11, and the folding blade is unfolded under the action of centrifugal force;

wherein, as shown in fig. 2, the flyback device comprises the connecting piece 1, the motor 2, the rotor 3, the magnetic elastic pieces 5 and at least two folding blades, the bottom end of the connecting piece 1 is connected with the body of the unmanned aerial vehicle, a cylindrical chute 6 is arranged in the connecting piece 1, a cover plate 7 for covering the chute 6 is arranged at the top end of the connecting piece 1, a first opening concentric with the axis of the chute 6 is arranged on the cover plate 7, one end of the magnetic elastic pieces 5 is connected on the cover plate 7, the other end of the magnetic elastic pieces 5 is provided with a hook 8, a plurality of magnetic elastic pieces 5 are circumferentially arranged along the chute 6, a plurality of electromagnet devices 4 are embedded in the connecting piece 1 and correspond to the plurality of magnetic elastic pieces 5 one by one, the bottom end of the motor 2 is provided with a first clamping platform 9 protruding outwards along the radial direction, a spring 10 in a compression state is arranged between the first clamping platform 9 and the cover plate 7, a plurality of hook portion of couple 8 is located the below card of first ka tai 9 is held motor 2, just motor 2's pivot 11 is worn out first opening and with rotor 3 is connected.

When the unmanned aerial vehicle flies or/and when the unmanned aerial vehicle is prepared to take off and return, if the rotor 3 is damaged, the magnetic elastic sheet 5 is controlled by the electromagnet device 4 to move away from the motor 2, the hook 8 for clamping the motor 2 is completely separated from the motor 2, and under the action of the spring 10, the motor 2 moves downwards along the chute 6, when the motor 2 moves downwards along the chute 6, the support piece 12 arranged on the folding blade is abutted against the rotor 3, the rotating shaft 11 of the motor 2 is completely separated from the rotor 3, and when the motor 2 moves downwards along the chute 6, the folding blade folded outside the connecting piece 1 is connected on the rotating shaft 11, and under the action of centrifugal force, the folding blade is unfolded, at the moment, the folding blade provides lifting force for the unmanned aerial vehicle, so as to ensure that the unmanned aerial vehicle can normally fly or/and normally take off, thereby reducing the loss of users, and does not endanger the life safety of others.

In the present application, the missed approach can be understood as follows:

1) when the unmanned aerial vehicle flies, if the rotor wing 3 of the unmanned aerial vehicle is damaged, the unmanned aerial vehicle re-flying device can keep a normal flying state, namely the unmanned aerial vehicle re-flying;

2) when unmanned aerial vehicle lands and carries out the operation in a certain place and finishes, then when preparing to take off and return, if rotor 3 takes place to damage, make unmanned aerial vehicle normally take off, make its normal taking off through the unmanned aerial vehicle device that flies again of this application, also can understand as making unmanned aerial vehicle fly again.

Wherein, unmanned aerial vehicle's body indicates: with rotor 3 on the unmanned aerial vehicle and the relevant part of connecting rotor 3 demolish the remaining part in back, connecting piece 1 accessible welding mode, threaded connection mode are connected with unmanned aerial vehicle's body.

The cover plate 7 and the connecting member 1 can be fixed by welding or screwing, and the cover plate 7 and the connecting member 1 can be integrally formed.

Wherein, the material of magnetic shrapnel 5 can be 304 stainless steel, 403 stainless steel, 410 stainless steel, 414 stainless steel, 416 stainless steel etc. still have certain elasticity when having magnetism, and can be by 2, 3, 4, 5 and more magnetic shrapnels 5 along 6 circumference of spout arrange, correspondingly, the quantity of magnetic shrapnel 5 also is 2, 3, 4, 5 and more, and all set up 1 magnetic shrapnel 5 with the corresponding position of every magnetic shrapnel 5 in connecting piece 1, and electromagnet device 4's structure is:

copper coils are wound on the iron core, and the acting force of the electromagnet device 4 and the magnetic shrapnel 5 can be accurately simulated and calculated through finite element software such as ANSYS or MAXWELL, so that current is input to the electromagnet device 4, and the hook 8 is ensured to be completely separated from the motor 2.

Wherein, the first clamping platform 9 can be in the following form:

1) the first clamping table 9 is in a ring shape protruding outwards along the radial direction of the motor 2, so that the hook part of the hook 8 can clamp the first clamping table 9;

2) the first clamping table 9 is a protrusion protruding outwards along the radial direction of the motor 2, and the number of the protrusions is the same as that of the magnetic spring pieces 5, that of the electromagnet devices 4 or that of the hooks 8, so that the hook part of each hook 8 can conveniently clamp each protrusion.

Wherein, the concrete structure of support 12 is: with the concentric annular post of the pivot 11 of motor 2, and the size relation between support piece 12 and the rotor 3 can be obtained through simple calculation, in order to guarantee motor 2 is followed when spout 6 moves down, support piece 12 offsets with rotor 3 so that pivot 11 with rotor 3 separates completely, and can set up a plurality of support piece 12.

Preferably, in the above technical solution, the missed approach device further includes: the folding blade comprises a fixed part 13 and a folding part 14 which is used for unfolding under the action of centrifugal force, the fixed part 13 is provided with the supporting part 12, and a 90-degree self-locking hinge 15 is arranged between the folding part 14 and the fixed part 13;

said unfolding of said folding blades under the effect of centrifugal force, comprising:

the folded portion 14 is unfolded by the centrifugal force.

Wherein, 90 degrees auto-lock articulated elements 15 can refer to folding hinge, exert an effort centrifugal force promptly to folding portion 14, and this effort centrifugal force promptly is greater than folding hinge's hinge power when, just can make folding portion 14 expand completely and folding portion 14 can not take place to rock to guarantee that unmanned aerial vehicle can steadily fly.

The fixing portion 13 and the supporting portion 12 can be fixed by welding or screwing.

Preferably, in the above technical solution, the missed approach device further includes: a second clamping table 16 with a polygonal cross section is arranged on the rotating shaft 11, and a second opening matched with the second clamping table 16 is formed in the rotor wing 3;

the unmanned aerial vehicle missed approach method also includes: before the motor 2 moves down along the chute 6, it is right that the second clamping table 16 and the second opening are clamped, so that the rotor 3 and the rotating shaft 11 rotate synchronously.

Before motor 2 along spout 6 moves down, to second ka tai 16 with the second opening carries out the joint, so that rotor 3 with pivot 11 carries out synchronous rotation.

The polygon may be a quadrangle, a pentagon, a hexagon, etc., and the hexagon is taken as an example, as shown in fig. 3, specifically:

fix the cross section for hexagonal second ka tai 16 and motor 2's pivot 11 through the welding mode, and be equipped with on rotor 3 with the second opening of second ka tai 16 adaptation, at this moment, second open-ended cross section also for using the hexagon, then carry out the joint with second ka tai 16 and second opening through interference fit's mode, in order to guarantee motor 2 is followed before 6 downstream of spout, rotor 3 carries out synchronous rotation with pivot 11, guarantees unmanned aerial vehicle's normal flight.

Preferably, in the above technical solution, the missed approach device further includes: the other end of the fixing part 13 is provided with a concave part matched with the second clamping table 16;

when the motor 2 moves down along the sliding chute 6, the folding paddle folded outside the connecting piece 1 is connected to the rotating shaft 11, and the folding paddle comprises:

when the motor 2 moves downwards along the sliding groove 6, the second clamping table 16 and the concave part are clamped, and the fixing part 13 is connected to the rotating shaft 11.

Follow at motor 2 during spout 6 downstream, through carrying out the joint to second ka tai 16 and depressed part, connect fixed part 13 on pivot 11, guarantee that folding paddle can rotate along with motor 2's pivot 11.

The second chuck 16 with a hexagonal cross section is taken as an example for illustration, specifically:

1) when the number of the folding blades is 2, each folding blade comprises 1 fixing part 13, and there are 2 depressed parts, as shown in fig. 4, at this time, one depressed part is a half hexagon, and two depressed parts form a complete hexagon, at this time, when the rotating shaft 11 rotates, the second clamping table 16 is driven to rotate, and when the second clamping table 16 rotates, the 2 depressed parts can automatically clamp the second clamping table 16 and rotate along with the second clamping table 16;

3) when the quantity of folding paddle is 3, this moment, a depressed part is 1/3 hexagons, and 3 depressed parts form a complete hexagon, and at this moment, when pivot 11 is when rotating, drive second ka tai 16 and rotate, when second ka tai 16 rotated, 3 depressed parts can automatic card hold second ka tai 16 to rotate along with second ka tai 16, when the quantity of folding paddle is more, analogizes with this.

It should be noted that: the distance that motor 2 moved down along spout 6 accessible calculation obtains to guarantee when motor 2 moved down along spout 6, offset with rotor 3 through support piece 12 that sets up on folding paddle, make motor 2's pivot 11 and rotor 3 separate completely, and make the folding paddle that folds in the connecting piece 1 outside connect in pivot 11.

Preferably, in the above technical solution, the missed approach device further includes: a bearing 17 concentric with the rotating shaft 11 is arranged at the top end of the motor 2, and a connecting rod 18 is arranged between the bearing 17 and the fixing part 13;

the unmanned aerial vehicle missed approach method also includes:

before the motor 2 moves downwards along the chute 6, the fixing part 13 is fixed through the connecting rod 18;

after the fixing part 13 is connected to the rotating shaft 11, the folding blade and the rotating shaft 11 rotate synchronously through the bearing 17.

The bearing 17 can be fixed on the top end of the motor 2 in a welding mode, or the bearing 17 is embedded into the top end of the motor 2, two ends of the connecting rod 18 are respectively connected with the fixing part 13 and the bearing 17 in a welding mode or a threaded connection mode, and the fixing part 13 is fixed through the connecting rod 18 before the motor 2 moves downwards along the sliding chute 6; the fixing part 13 is connected behind the rotating shaft 11, and a bearing 17 is used for ensuring that the folding blades rotate synchronously with the rotating shaft 11.

Preferably, in the above technical solution, the method further comprises:

acquiring the lift force of each rotor wing 3 of the unmanned aerial vehicle, judging the lift force of each rotor wing 3 and a preset lift force one by one, and determining whether the rotor wing 3 is damaged or not according to a comparison result; it is determined whether to issue the command to the electromagnet device 4 according to the damage result.

By acquiring the lift force of each rotor wing 3 of the unmanned aerial vehicle, judging the lift force of each rotor wing 3 and the preset lift force one by one, and determining whether the rotor wing 3 is damaged or not according to the comparison result; according to the damage result, whether to send the instruction to electromagnet device 4 is confirmed, and is simple and convenient, specifically:

1) when the lift force of at least one rotor wing 3 of the unmanned aerial vehicle is smaller than the preset lift force, determining that at least one rotor wing 3 is damaged, and sending a command for controlling the magnetic elastic sheet 5 to move away from the motor 2 to the electromagnet device 4 corresponding to the at least one rotor wing 3;

2) when the lift force of each rotor wing 3 of the unmanned aerial vehicle is greater than the preset lift force, it is determined that no rotor wing 3 is damaged, and at the moment, a command for controlling the magnetic elastic sheet 5 to move away from the motor 2 is not sent to the electromagnet device 4;

wherein, supposing that the unmanned aerial vehicle has 4 rotors 3, as is well known, when the resultant force of the lift forces of the 4 rotors 3 is greater than the gravity of the unmanned aerial vehicle, the unmanned aerial vehicle can take off, so that the lift force of each rotor 3 is G/4, wherein G represents the gravity of the unmanned aerial vehicle, and the preset lift force can be set to be G/4;

wherein, the lift of each rotor 3 can be obtained by arranging a pressure sensor on each connecting piece 1, specifically:

1) the piezoelectric sensor can be arranged on the folding blade, particularly the fixing part 13 of the folding blade, when the rotor 3 rotates, a downward acting force can be generated, at the moment, the acting force can enable the piezoelectric sensor to generate an electric signal, the lifting force of each rotor 3 can be obtained by analyzing the electric signal, before the piezoelectric sensor is applied, the functional relation between the electric signal returned by the pressure sensor and the lifting force can be accurately obtained through multiple comparison experiments, when the piezoelectric sensor is applied, the upgrading of each rotor 3 can be accurately obtained through the functional relation, and therefore, a more accurate comparison result can be obtained;

2) a high-precision pressure sensor can be arranged on the folding blade, particularly on the fixing part 13 of the folding blade, for example, the precision is +/-0.05% FS, +/-0.025% FS, etc., when the rotor 3 rotates, a downward acting force can be generated, and the lift force of each rotor 3 can be accurately obtained through the high-precision pressure sensor;

3) the lift of each rotor 3 can be calculated by monitoring the airflow through the drone rotors 3 using a light pressure sensor developed by AERS-Midwest.

Preferably, in the above technical solution, a buckle 19 is provided between the folding portion 14 and the connecting member 1 to prevent the folding portion 14 from unfolding before the motor 2 moves down along the chute 6, wherein the buckle 19 may be in the following form:

1) the buckle 19 is a long rod, one end of the long rod is connected with the folding part 14 in an interference fit mode, and one end of the long rod is fixedly connected with the connecting piece 1 in a threaded connection mode or a welding mode so as to prevent the folding part 14 from unfolding before the motor 2 moves downwards along the sliding groove 6;

when the motor 2 moves downwards along the sliding chute 6, the folding part 14 rotates, and centrifugal force is generated at the moment, so that the connection relation between the long rod and the folding part 14 is broken, and the folding part 14 can be unfolded normally;

it should be noted that: before the buckle 19 is applied, a plurality of comparison experiments are carried out to ensure that the connection relationship between the long rod and the folding part 14 can be broken under the action of centrifugal force, so that the folding part 14 can be normally unfolded;

2) the buckle 19 is a section of steel wire and a button, specifically, one end of the steel wire is fixedly connected with the connecting piece 1 in a welding mode, the other end of the steel wire is connected with the secondary end of the button in a welding mode, the female end of the button is arranged at the corresponding position of the folding part 14, and the folding part 14 is effectively prevented from unfolding before the motor 2 moves downwards along the chute 6 through the connection of the secondary end and the female end;

when the motor 2 moves downwards along the chute 6, the folding part 14 rotates, and centrifugal force is generated at the moment, so that the connection relation between the male end and the female end of the button is broken, and the folding part 14 can be unfolded normally;

it should be noted that: before the buckle 19 is applied, a plurality of comparison experiments should be performed to ensure that the connection relationship between the male end and the female end of the button can be broken under the action of centrifugal force, so that the folding part 14 can be normally unfolded.

In the above embodiments, although the steps are numbered as S1, S2, etc., but only the specific embodiments are given in the present application, and those skilled in the art can adjust the execution sequence of S1, S2, etc. according to the actual situation, which is also within the protection scope of the present invention.

In the present invention, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.