CN113911342A

CN113911342A - Bionic flapping wing micro aircraft capable of realizing controllable flapping amplitude based on elastic energy storage of wing root

Info

Publication number: CN113911342A
Application number: CN202111311622.2A
Authority: CN
Inventors: 吴江浩; 程诚; 曹赫宇
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2022-01-11
Anticipated expiration: 2041-11-08
Also published as: CN113911342B

Abstract

The invention discloses a bionic flapping wing micro air vehicle capable of realizing controllable flapping amplitude based on elastic energy storage of a wing root. According to the invention, the wing root elastic stop structure is introduced into the aircraft, so that the inertial work of flapping of the wing rod is stored into elastic potential energy at the flapping ending and starting stages, and is released at the next flapping initial stage of the flapping wing, on one hand, the transmission efficiency of the aircraft is improved, the energy dissipation of the aircraft is reduced, on the other hand, the movement of the flapping wing in the process of switching the upward flapping movement and the downward flapping movement is accelerated, the overturning time of the flapping wing is reduced, and the pneumatic efficiency of the flapping wing is improved; meanwhile, the three rotary steering engines, the pulleys and the cams can realize the differential adjustment of flapping amplitude of the bionic flapping wing under the condition of not changing the operation of a transmission mechanism, realize the bionic flapping control motion and realize the three-axis controllable flight of the bionic flapping wing micro aircraft.

Description

Bionic flapping wing micro aircraft capable of realizing controllable flapping amplitude based on elastic energy storage of wing root

Technical Field

The invention relates to the field of micro aircrafts, in particular to a bionic flapping wing micro aircraft capable of realizing controllable flapping amplitude based on elastic energy storage of a wing root.

Background

The concept of micro-miniature aircraft was proposed by the united states department of defense advanced research project in the nineties of the last century, and with the rapid development of MEMS processing and computer technologies, the concept of micro-miniature aircraft became increasingly realistic. The micro aircraft has wide application prospect in military and civil fields such as reconnaissance and monitoring, post-disaster search and rescue, pipeline inspection and the like. The size of the insect in nature is equivalent to that of a microminiature aircraft, and the insect-killing aircraft has extremely strong maneuverability and aerodynamic efficiency. Thus, scientists have developed the concept of a bionic flapping wing micro-aircraft based on the principle of insect flight. The flapping motion of the bionic flapping wing micro air vehicle is similar to flapping of insect wings, and can generate higher lift force under the conditions of small size and low speed flight.

The development of the existing bionic flapping wing micro air vehicle still faces a plurality of difficulties. On the one hand, since it is difficult to achieve the flexibility of the bio-muscles with artificial structures, it is difficult to achieve the complex flapping motion of the insect wings to generate the control moment required for controllable flight. Insects usually generate control torque in two ways, namely, actively controlling the change of an attack angle of wings in a flapping cycle, and changing the aerodynamic force of different flapping stages of left and right wings so as to generate control torque; the other is to actively control the flapping motion of the wings, which comprises the change of the flapping amplitude or the flapping plane, and changes the magnitude or the direction of the aerodynamic force of the left wing and the right wing, thereby generating a control moment. In the existing bionic flapping wing micro air vehicle, a scheme of controlling an attack angle is mostly adopted, and a scheme of controlling flapping motion is rare. The mechanism of the attack angle control scheme is simple, but the attack angle of the flapping wing is changed in one flapping cycle, so that the flapping of the flapping wing at the optimal attack angle cannot be always kept at the optimal efficiency, and the aerodynamic efficiency of the flapping wing is influenced in the control process, so that the endurance time is influenced; in addition, because the wing membrane is made of flexible materials, the attack angle of the wing membrane is difficult to control accurately, and higher requirements are provided for a control system. The scheme for controlling flapping motion can realize the generation of control moment by changing the flapping amplitude and the flapping average position of the left wing and the right wing, and ensure that the attack angle of the flapping wings is always kept unchanged at a high-efficiency attack angle, but because the transmission structure of the bionic flapping wing micro air vehicle is usually in a high-speed rotation state, the transmission structure is often difficult to control so as to change the flapping motion.

On the other hand, most of the bionic flapping wing micro aircrafts disclosed at present use a connecting rod structure to realize bionic flapping motion, when the flapping wings of the aircrafts move to the ultimate flapping position of the mechanism design in the up-and-down flapping process, the flapping wings are often driven to continue to move due to the driving of the inertial loads of the wing rods and the flapping wings, so that the transmission connecting rod structure enters a state with poor transmission stress or a dead point position, the transmission efficiency is reduced, and the endurance time of the aircrafts is influenced. Meanwhile, the part of inertial load is dissipated through structural deformation, rivet collision, motor stalling and other forms, various problems such as flapping motion deformation, motor efficiency reduction and the like are caused, and the problems of aircraft lift force reduction, endurance time reduction and the like are further caused.

Therefore, the bionic flapping wing micro air vehicle which can solve the problem of inertial load storage application of the flapping wings at flapping limit positions needs to be invented, the flapping motion amplitude can be adjusted based on the scheme, and a flight control method of the bionic flapping wing micro air vehicle is further developed.

Disclosure of Invention

The invention provides a bionic flapping wing micro air vehicle capable of realizing controllable flapping amplitude based on elastic energy storage of a wing root. The aircraft can convert inertial work of the flapping wings into elastic potential energy when the wings are close to the extreme positions of up-down flapping and release the elastic potential energy at the subsequent flapping starting stage, so that the energy dissipation of a transmission mechanism is reduced, the overturning time of the flapping wings is reduced, and the aerodynamic efficiency of the flapping wings is improved. In addition, the aircraft can adjust the flapping amplitude and the average flapping angle position of the left flapping wing and the right flapping wing through the three steering engines, and the three-axis control of the aircraft is realized on the premise that the flapping wings are always at a high aerodynamic efficiency point in the control process.

A bionic flapping wing micro air vehicle capable of realizing controllable flapping amplitude based on elastic energy storage of a wing root comprises a transmission system, a control system, a lift system and a power system.

The transmission system comprises a transmission base, a supporting base, a distribution gear speed reduction set, a connecting rod and a transmission amplifying device. The transmission base is used for fixing the distribution gear reduction group and the power device, and the support base is used for fixing the positions of the transmission amplifying device, the control executing mechanism of the control system and the tensioning rope of the constraint control system. The distribution gear reduction unit comprises a main shaft gear and a reduction unit gear, the main shaft gear is arranged on an output shaft of the power device, and the reduction unit gear is composed of a plurality of gears, is meshed with the main shaft gear and reduces the high-speed movement of the power device. One end of the connecting rod is connected to an eccentric hole position of the tail end speed reduction group gear, the other end of the connecting rod is coaxially connected with the transmission amplifying device through a rivet and slides smoothly in the supporting base restraining sliding groove to form a crank sliding block mechanism, and circular motion after the speed reduction of the distributed gear speed reduction group is changed into linear reciprocating sliding in a horizontal plane of the connecting rod. The transmission amplifying device is of a rod system structure, all the component rod pieces are fixed on the mounting hole positions of the supporting base through rivets, the linear reciprocating sliding in the horizontal plane of the connecting rod is changed into the reciprocating flapping of the wing, and meanwhile, the reciprocating flapping amplitude of the wing is amplified, so that the generation of aerodynamic force is improved.

The control system comprises an elastic stop mechanism and a control execution mechanism. The elastic stopping mechanism consists of a left elastic stopping mechanism and a right elastic stopping mechanism which are respectively used for restricting the limit positions of the left flapping wing and the right flapping wing, and the left elastic stopping mechanism and the right elastic stopping mechanism are the same and respectively consist of a supporting cylinder, a wing rod stopping piece, a spring connecting piece and a spring. The supporting cylinder is fixedly connected in the corresponding hole position of the supporting base through a rivet, and circular ring grooves are distributed on the side surface of the supporting cylinder and used for restraining the wing rod stop piece, the spring connecting piece, the spring and the tensioning rope of the control actuating mechanism. The outer side of the wing rod stop part is provided with a flat plate structure for restricting the flapping-wing flapping limit position, the inner side of the wing rod stop part is connected with a spring, the other end of the spring is connected with a spring connecting piece, the spring connecting piece is simultaneously connected with a tensioning rope of a control execution mechanism, and the wing rod stop part and the spring connecting piece can circumferentially slide around a circular groove of a supporting cylinder. When the flapping wings are close to the extreme flapping positions, the wing rod stop parts slide along the circular groove, the position of the spring connecting piece restrained by the tensioning rope keeps unchanged, the spring is compressed at the moment to realize the elastic energy storage function, and when the inertia force and the kinetic energy of the flapping wings are completely converted into the elastic potential energy of the spring, the flapping wings reach the extreme flapping positions.

The control executing mechanism comprises a control supporting base, a rotary steering engine, a pulley, a cam and a tensioning rope. The control support base main part is the dull and stereotyped structure for the installation rotatory steering wheel, and the control supports the base and carries out the riveting through the locating hole on the projection of both ends and the hole of supporting the base both ends and link firmly. The rotary steering engine comprises a left rotary steering engine, a right rotary steering engine and a middle rotary steering engine. The output ends of the left and right rotary steering engines are coaxially connected with the pulley and can drive the pulley to rotate forwards or backwards, the output end of the middle rotary steering engine is coaxially connected with the cam and can drive the cam to rotate forwards or backwards, and the side edges of the pulley and the cam are provided with annular grooves which are respectively used for restraining the tensioning rope.

The lift system comprises a left flapping wing and a right flapping wing, and each flapping wing consists of a main beam, a flexible beam, a vertical beam and a wing membrane. The wing membrane is a flexible membrane and is made of polyimide material, and the front edge and the side edge of the wing membrane are respectively wrapped into a tube shape and then fixed by using an adhesive. The main beam and the vertical beam respectively penetrate through the tubular space formed by the front edge and the side edge of the wing membrane and can freely rotate around the tubular space. The vertical beam is overlapped below the main beam at an angle of 90 degrees, and the flexible beam is bonded on one side of the wing membrane and forms an included angle of 30 degrees with the main beam; the wing root end of the main beam is connected with a wing rod of the transmission system.

The power system is a power source of the bionic flapping wing aircraft, and the flapping motion of the flapping wings is realized by the driving system mechanism. The power system consists of a power device, wherein the power device can be a hollow cup motor or a brushless motor.

A bionic flapping wing micro aircraft based on wing root elastic energy storage and with controllable flapping amplitude comprises the following wing root energy storage and release processes:

(1) when the flapping wing approaches the extreme position of the upper flap or the lower flap and is about to exceed the designed flap amplitude range under the action of inertial load, the connecting rod driving the flapping wing to rotate contacts the wing rod stop piece, the wing rod stop piece is driven to rotate along the circular groove of the supporting cylinder, and the wing rod stop piece further drives the spring to start to compress;

(2) the other end of the spring is connected with a spring connecting piece, when the control actuating mechanism is kept still, the spring connecting piece is restrained by the tensioning rope, the position is kept still, the spring is compressed in the process, the kinetic energy transmitted by the wing rod stop piece is converted into elastic potential energy, and resistance opposite to the movement direction of the flapping wing is applied to the connecting rod for driving the flapping wing to rotate through the wing rod stop piece, so that the current flapping process is finished more quickly;

(3) the flapping wing kinetic energy is converted into the elastic potential energy of the spring along with the end of the upward flapping or downward flapping process of the flapping wing, then the spring gradually releases the elastic potential energy, the spring exerts force on the connecting rod which drives the flapping wing to rotate through the wing rod stop piece, the subsequent downward flapping or upward flapping process of the flapping wing is accelerated until the elastic potential energy of the spring is completely released, and the wing rod stop piece is restored to the initial stop position.

In the process, on one hand, the spring accelerates the ending process of the upward flapping or downward flapping and the starting process of the downward flapping or upward flapping of the flapping wing, so that the overturning time of the flapping wing is reduced, and the pneumatic efficiency of the flapping wing is improved; on the other hand, the springs convert the inertia work of the flapping wings into elastic potential energy and then release the elastic potential energy to be applied to the flapping wings, so that the inertia work of the flapping wings is effectively utilized, the energy loss of a transmission mechanism is reduced, meanwhile, the springs with different rigidity can ensure the maximum flapping amplitude of the flapping wings, and the elastic limit function is realized.

A bionic flapping wing micro aircraft pitching control moment generation process based on wing root elastic energy storage and capable of realizing controllable flapping amplitude is as follows: when the aircraft needs to produce pitching control moment, left and right rotatory steering wheel reverse rotation, the tensioning rope reverse rotation who drives control actuating system through the pulley respectively, order about the spring coupling spare and the wing pole stopper clockwise rotation (or anticlockwise rotation) of clapping on the left side restriction, the spring coupling spare and the wing pole stopper clockwise rotation (or anticlockwise rotation) of clapping down in the left side restriction, the spring coupling spare and the wing pole stopper anticlockwise rotation (or clockwise rotation) of clapping on the right side restriction, the spring coupling spare and the wing pole stopper anticlockwise rotation (or clockwise rotation) of clapping down in the right side restriction, thereby the limit position of clapping simultaneously clockwise rotation (or anticlockwise rotation) with the limit position of clapping down on the left side flapping wing, limit position and the limit position of clapping down on the right side flapping wing are simultaneously anticlockwise rotation (or clockwise rotation). In the process, the middle rotary steering engine is kept still, the flapping amplitudes of the left flapping wing and the right flapping wing are unchanged, the average position of the flapping angles moves forwards or backwards simultaneously, the action points of the aerodynamic force move forwards (or backwards) simultaneously under the condition that the aerodynamic force generated by flapping motion is approximately unchanged, and the raising moment (or the lowering moment) is generated before the steering engine rotates.

A generating process of rolling control torque of a bionic flapping wing micro aircraft based on wing root elastic energy storage is as follows: when the aircraft needs to produce roll control moment, left and right rotatory steering wheel syntropy is rotatory, the tensioning rope syntropy that drives control actuating system through the pulley respectively drives, order about the spring coupling spare and the wing pole stopper clockwise rotation (or anticlockwise rotation) of clapping on the left side restriction, the spring coupling spare and the wing pole stopper anticlockwise rotation (or clockwise rotation) of clapping down in the left side restriction, the spring coupling spare and the wing pole stopper clockwise rotation (or anticlockwise rotation) of clapping on the right side restriction, the spring coupling spare and the wing pole stopper anticlockwise rotation (or clockwise rotation) of clapping down in the right side restriction, thereby the last limit position of clapping of left side flapping wing and right side flapping wing clockwise rotation (or anticlockwise rotation) simultaneously, the limit position of clapping down of left side flapping wing and right side flapping wing anticlockwise rotation (or clockwise rotation) simultaneously. In the process, the rotary steering engine is kept still, the flapping amplitude of the left flapping wing is increased (or reduced), the flapping amplitude of the right flapping wing is reduced (or increased), and the flapping average position of the left wing rod and the right wing rod is unchanged, so that the aerodynamic force generated by the flapping motion of the left flapping wing is increased (or reduced), the aerodynamic force generated by the flapping motion of the right flapping wing is reduced (or increased), and compared with the steering engine before rotation, the right rolling moment (or the left rolling moment) is generated.

A bionic flapping wing micro aircraft yaw control moment generation process based on wing root elastic energy storage and controllable flapping amplitude is as follows:

when the aircraft needs to generate yaw control moment, the left and right rotary steering engines are kept still, the middle rotary steering engine drives the cam to rotate clockwise (or anticlockwise), and due to the change of the diameter of the cam, one side of the tensioning rope on two sides of the cam is tensioned, and the other side of the tensioning rope is loosened. The left side is driven to limit the spring connecting piece and the wing rod stop piece which are upwards clapped to rotate anticlockwise (or rotate clockwise), the left side is limited to limit the spring connecting piece and the wing rod stop piece which are downwards clapped to rotate clockwise (or rotate anticlockwise), the right side is limited to limit the spring connecting piece and the wing rod stop piece which are upwards clapped to rotate clockwise (or rotate anticlockwise), the right side is limited to limit the spring connecting piece and the wing rod stop piece which are downwards clapped to rotate anticlockwise (or rotate clockwise), and therefore the upper clapping limit position of the left side flapping wing and the lower clapping limit position of the right side flapping wing rotate clockwise (or rotate anticlockwise) at the same time. The flapping amplitude of the left flapping wing and the flapping amplitude of the right flapping wing are unchanged, and the average flapping positions of the left flapping wing and the right flapping wing simultaneously rotate anticlockwise (or clockwise), so that the lateral force of the left flapping wing and the right flapping wing generates a left yaw moment (or right yaw) because the rotating points of the left flapping wing and the right flapping wing are not coincident with the gravity center of the aircraft.

The invention has the advantages that:

(1) the utility model provides a bionical flapping wing micro air vehicle of controllable range of flapping is realized based on wing root elastic energy storage, through wing root elasticity backstop structure, stores the inertial work of wing pole flapping in-process as elastic potential energy to again convert elastic potential energy into the kinetic energy of flapping wing motion at the flapping wing next initial stage, improved aircraft transmission efficiency, reduce the energy dissipation of aircraft, can reduce the vibration problem that the aircraft caused because inertial load is too big simultaneously.

(2) A bionic flapping wing micro air vehicle capable of realizing controllable flapping amplitude based on elastic energy storage of wing roots accelerates the movement of flapping wings in the conversion process of upward flapping and downward flapping movements through an elastic wing root stop structure, reduces the overturning time of the flapping wings, and accordingly improves the pneumatic efficiency of the flapping wings.

(3) A bionic flapping wing micro aircraft capable of realizing controllable flapping amplitude based on wing root elastic energy storage can design the flapping amplitude limit position of flapping wings through a wing root elastic stop structure and reasonable spring selection, effectively prevents the flapping wings from entering the working point with poor transmission stress state, ensures that a transmission mechanism is in a high-efficiency operation working area, and is an effective flapping amplitude limiter.

(4) A bionic flapping wing micro air vehicle capable of realizing controllable flapping amplitude based on elastic energy storage of a wing root can realize differential adjustment of flapping amplitude of flapping wings under the condition of not changing the operation of a transmission mechanism through three rotary steering gears, pulleys and cams, realize bionic flapping control motion and realize three-axis controllable flight of the bionic flapping wing micro air vehicle.

Drawings

FIG. 1 is an overall schematic diagram of a bionic flapping wing micro-aircraft with controllable flapping amplitude based on elastic energy storage of a wing root;

FIG. 2 is a partial schematic view of a transmission system of a bionic flapping wing micro air vehicle for realizing controllable flapping amplitude based on elastic energy storage of a wing root;

FIG. 3 is a schematic diagram of a part of a control system of a bionic flapping wing micro air vehicle for realizing controllable flapping amplitude based on elastic energy storage of a wing root;

FIG. 4 is a schematic diagram of a control system of a bionic flapping wing micro air vehicle for realizing controllable flapping amplitude based on elastic energy storage of a wing root;

FIG. 5 is a schematic diagram of a lift system of a bionic flapping wing micro air vehicle for realizing controllable flapping amplitude based on elastic energy storage of a wing root;

in the figure:

1-transmission system 2-control system 3-lift system

4-power system

101-transmission base 102-support base 103-spindle gear

104-single layer gear 105-double layer gear 106-connecting rod

107-left rocker arm 108-left connecting rod 109-left wing rod

110-right rocker arm 111-right connecting rod 112-right wing rod

201-support cylinder one 202-wing rod stop one 203-spring connection one

204-wing lever stop two 205-spring connector two 206-spring one

207-spring two 208-control support base 209-left rotary steering engine

210-left pulley 211-middle rotary steering engine 212-cam

213-right rotary steering engine 214-right pulley 215-tension rope I

216-tension rope two 217-support cylinder two 218-wing rod stop three

219-spring link three 220-wing lever stop four 221-spring link four

222-spring three 223-spring four

301-main beam 302-flexible beam 303-vertical beam

304-wing membrane

401-power plant

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

As shown in figure 1, the bionic flapping amplitude flapping wing micro air vehicle based on the elastic energy storage of the wing root comprises a transmission system 1, a control system 2, a lift system 3 and a power system 4.

Fig. 2 shows an exemplary embodiment of the transmission system 1, wherein the transmission system 1 comprises a transmission base 101, a support base 102, a distribution gear reduction group, a connecting rod 106 and a transmission amplifying device. The transmission base 101 comprises mounting holes of the distribution gear reduction group and mounting cavities of the power device 401, and is used for fixing the distribution gear reduction group and the power device 401. The supporting base 102 includes a transmission amplifying device mounting hole, a constraint chute, a control actuator mounting hole, and four ribs, which are respectively used for fixing the transmission amplifying device of the transmission system, the control actuator of the control system, and the tensioning rope of the constraint control system. The distribution gear reduction group comprises a main shaft gear 103, a single-layer gear 104 and a double-layer gear 105. The main shaft gear 103 is mounted on an output shaft of the power device 401, the single-layer gear 104 and the double-layer gear 105 are respectively mounted in predetermined hole positions of the transmission base 101, a large-tooth-number gear in the double-layer gear 105 is meshed with the main shaft gear 103, and a small-tooth-number gear is meshed with the single-layer gear 104. One end of the connecting rod 106 is connected to the eccentric hole of the single-layer gear 104, and the other end is coaxially connected with one end of the left rocker arm 107 and one end of the right rocker arm 110 of the transmission amplifying device through rivets, and slides smoothly in the constraint sliding groove of the supporting base 102. The transmission amplifying device comprises a left rocker arm 107, a left connecting rod 108, a left wing rod 109, a right rocker arm 110, a right connecting rod 111 and a right wing rod 112, wherein the left rocker arm 107 and the right rocker arm 110 are riveted with corresponding mounting holes of the support base 102 through middle mounting holes respectively and can rotate around the middle mounting holes. The left end of the left rocker arm 107 is connected with the right end of the left connecting rod 108 through a rivet, the left end of the left connecting rod 1018 is connected with a hole in the middle of the left wing rod 109 through a rivet, the right end of the left wing rod 109 is riveted with a corresponding mounting hole of the support base 102, and the left wing rod 109 is driven by the left connecting rod 108 to flap around the mounting hole in a reciprocating manner. The right end of the right rocker arm 110 is connected with the left end of a right connecting rod 111 through a rivet, the right end of the right connecting rod 111 is connected with a hole in the middle of a right wing rod 112 through a rivet, the left end of the right wing rod 112 is riveted with a corresponding mounting hole of the support base 102, and the right wing rod 112 swings around the mounting hole in a reciprocating manner. The transmission amplifying device changes the linear reciprocating sliding in the horizontal plane of the connecting rod into the reciprocating flapping of the wing on one hand, and amplifies the reciprocating flapping amplitude in a limited space on the other hand, thereby improving the generation of aerodynamic force.

Fig. 3 and 4 illustrate an exemplary embodiment of a control system 2 that includes a left spring stop mechanism, a control actuator, and a right spring stop mechanism.

The left elastic stopping mechanism consists of a first supporting cylinder 201, a first wing rod stopping part 202, a first spring connecting piece 203, a second wing rod stopping part 204, a second spring connecting piece 205 and two springs. The first support cylinder 201 is used for restraining a tension rope of the wing rod stop part, the spring connecting part, the spring and the control execution mechanism, the first support cylinder 201 is fixedly connected in a corresponding hole position of the support base 102 through rivets, and four circular grooves are sequentially distributed on the side face of the first support cylinder 201 from high to low and are respectively a first circular groove, a second circular groove, a third circular groove and a fourth circular groove. The first wing rod stop part 202 and the second wing rod stop part 204 are consistent in structure, the inner side of the first wing rod stop part 202 is of an arc-shaped structure with a central angle of 30 degrees, the arc-shaped structure can be inserted into a circular groove of a supporting cylinder and can circumferentially slide around the circular groove of the supporting cylinder, the first wing rod stop part 202 is inserted into a first circular groove of the supporting cylinder 201, the second wing rod stop part 204 is inserted into a fourth circular groove of the supporting cylinder 201, the side edges of the circular structures of the first wing rod stop part 202 and the second wing rod stop part 204 are semi-circular ring structures and are respectively used for being connected with one end of a first spring 206 and one end of a second spring 207, and the outer sides of the first wing rod stop part 202 and the second wing rod stop part 204 are of rectangular flat plate structures and used for stopping a convex column at the lower end of a wing rod. The first spring connecting piece 203 and the second spring connecting piece 205 are consistent in structure, the inner side of the spring connecting piece is divided into an upper layer and a lower layer, the upper layer and the lower layer are both arc-shaped structures with a central angle of 30 degrees, the height of the upper layer arc-shaped structure is slightly higher than that of the lower layer arc-shaped structure, the upper layer arc-shaped structure of the first spring connecting piece 203 is inserted into the first circular groove of the first support cylinder 201, the lower layer arc-shaped structure of the first spring connecting piece 203 is inserted into the second circular groove of the first support cylinder 201, the lower layer arc-shaped structure of the second spring connecting piece 205 is inserted into the third circular groove of the first support cylinder 201, the upper layer arc-shaped structure of the second spring connecting piece 205 is inserted into the fourth circular groove of the first support cylinder 201, the first spring connecting piece 203 and the second spring connecting piece 205 can circumferentially slide around the circular grooves of the first support cylinder 201, the upper circular arc side edge and the lower circular arc side edge of the spring connecting piece are respectively provided with a semicircular ring structure, wherein, the semicircular ring structure of the upper end circular arc lateral edge is used for being connected with the other end of the spring, the semicircular ring structure of the lower end circular arc lateral edge is used for being connected with one end of a tensioning rope of the control execution mechanism, and the upper layer circular arc and the lower layer circular arc of the spring connecting piece are connected through a reverse C-shaped cylindrical structure. The two ends of the first spring 206 are respectively connected with the semicircular ring structure of the side edge of the first wing rod stop part 202 and the semicircular ring structure of the side edge of the upper layer arc structure of the first spring connecting part 203, and are placed in the first circular ring groove of the first support cylinder 201, and the two ends of the second spring 207 are respectively connected with the semicircular ring structure of the side edge of the second wing rod stop part 204 and the semicircular ring structure of the side edge of the upper layer arc structure of the second spring connecting part 205, and are placed in the fourth circular ring groove of the first support cylinder 201.

The control executing mechanism comprises a control supporting base 208, a left rotating steering engine 209, a left pulley 210, a middle rotating steering engine 211, a cam 212, a right rotating steering engine 213, a right pulley 214, a first tensioning rope 215 and a second tensioning rope 216. The main body of the control support base 208 is of a flat plate structure, three rotary steering engine mounting hole positions are reserved on the flat plate and are respectively used for mounting a left rotary steering engine 209, a middle rotary steering engine 211 and a right rotary steering engine 213, two ends of the control support base 208 are of convex column structures, each convex column structure is provided with a positioning hole, the control support base 208 is fixedly connected with holes at two ends of the support base 102 in a riveting mode through the positioning holes on the convex columns at two ends, the left rotary steering engine 209 is mounted in a reserved mounting hole position of the control support base 208, the output end of the left rotary steering engine is coaxially connected with the left pulley 210 and can drive the left pulley 210 to rotate forwards or backwards, the left pulley 210 is of a cylindrical structure, the side edge is provided with an annular groove for restraining a tension rope 216, the middle rotary steering engine 211 is fixed in the reserved mounting hole position of the control support base 208, the output end of the middle rotary steering engine is coaxially connected with the cam 212 and can drive the cam 212 to rotate forwards or backwards, the cam 212 is provided with an annular groove at the side edge, the right rotary steering engine 213 is arranged in a reserved mounting hole of the control support base 208, the output end of the right rotary steering engine is coaxially connected with the right pulley 214 and can drive the right pulley 214 to rotate forwards or backwards, the right pulley 214 is of a cylindrical structure, and the side edge of the right pulley is provided with an annular groove for restraining the tension rope II 216.

The right elastic stopping mechanism consists of a second supporting cylinder 217, a third wing rod stopping piece 218, a third spring connecting piece 219, a fourth wing rod stopping piece 220, a fourth spring connecting piece 221 and two springs. The second supporting cylinder 217 is used for restraining a tension rope of the wing rod stop member, the spring connecting member, the spring and the control actuating mechanism, the second supporting cylinder 217 is fixedly connected in a corresponding hole of the supporting base 102 through a rivet, and four circular grooves, namely a first circular groove, a second circular groove, a third circular groove and a fourth circular groove, are sequentially distributed on the side surface of the second supporting cylinder 217 from high to low. The third wing rod stop part 218 and the fourth wing rod stop part 220 are consistent in structure, the inner side of the third wing rod stop part is of an arc-shaped structure with a central angle of 30 degrees, the arc-shaped structure can be inserted into a circular groove of the support cylinder and can circumferentially slide around the circular groove of the support cylinder, the third wing rod stop part 218 is inserted into a first circular groove of the second support cylinder 217, the fourth wing rod stop part 220 is inserted into a fourth circular groove of the second support cylinder 217, the side edge of the circular structure of the third wing rod stop part 218 and the fourth wing rod stop part 220 is of a semicircular structure and is respectively used for being connected with one end of the third spring 222 and one end of the fourth spring 223, and the outer side of the third wing rod stop part 218 and the fourth wing rod stop part 220 is of a rectangular flat plate structure and used for stopping a convex column at the lower end of the wing rod. The third spring connecting piece 219 and the fourth spring connecting piece 221 are consistent in structure, the inner side of the spring connecting piece is divided into an upper layer and a lower layer, the upper layer and the lower layer are both arc-shaped structures with a central angle of 30 degrees, the height of the upper layer arc-shaped structure is slightly higher than that of the lower layer arc-shaped structure, the upper layer arc-shaped structure of the third spring connecting piece 219 is inserted into a first circular groove of the second support cylinder 217, the lower layer arc-shaped structure of the third spring connecting piece 219 is inserted into a second circular groove of the second support cylinder 217, the lower layer arc-shaped structure of the fourth spring connecting piece 221 is inserted into a third circular groove of the second support cylinder 217, the upper layer arc-shaped structure of the fourth spring connecting piece 221 is inserted into a fourth circular groove of the second support cylinder 217, the third spring connecting piece 219 and the fourth spring connecting piece 221 can circumferentially slide around the circular grooves of the second support cylinder 217, the upper circular arc side edge and the lower circular arc side edge of the spring connecting piece are respectively provided with a semicircular ring structure, wherein, the semicircular ring structure of the upper end circular arc lateral edge is used for being connected with the other end of the spring, the semicircular ring structure of the lower end circular arc lateral edge is used for being connected with one end of a tensioning rope of the control execution mechanism, and the upper layer circular arc and the lower layer circular arc of the spring connecting piece are connected through a reverse C-shaped cylindrical structure. Two ends of the third spring 222 are respectively connected with the semicircular ring structure of the side edge of the third wing rod stop part 218 and the semicircular ring structure of the side edge of the upper layer arc structure of the third spring connecting part 219, and are placed in the first circular ring groove of the second support cylinder 217, and two ends of the fourth spring 223 are respectively connected with the semicircular ring structure of the side edge of the fourth wing rod stop part 220 and the semicircular ring structure of the side edge of the upper layer arc structure of the fourth spring connecting part 221, and are placed in the fourth circular ring groove of the second support cylinder 217.

Fig. 5 shows an exemplary embodiment of the lift system 3. The lifting system 3 consists of a left flapping wing and a right flapping wing, and each flapping wing consists of a main beam 301, a flexible beam 302, a vertical beam 303 and a wing membrane 304. The wing membrane 304 is a flexible membrane made of polyimide, and the front edge and the side edge of the wing membrane 304 are respectively wrapped into a tubular shape and then fixed by using an adhesive. The main beam 301 and the vertical beam 303 respectively penetrate through the tubular space formed by the front edge and the side edge of the wing membrane 304 and can freely rotate around the tubular space. The vertical beam 303 is overlapped below the main beam 301 at an angle of 90 degrees, and the flexible beam 302 is adhered to one side of the wing membrane and forms an included angle of 30 degrees with the main beam 301; the main beam 301 is connected with the wing rod of the transmission system at the wing root end.

The power system is a power source of the bionic flapping wing aircraft, and the flapping motion of the flapping wings is realized by the driving system mechanism. The power system consists of a power plant 401, wherein the power plant 401 may be a coreless motor or a brushless motor.

The process of the wing root energy storage and release of the bionic flapping wing micro aircraft based on the wing root elastic energy storage of the invention is described by combining the figures 1-5 as follows:

taking the process of 'end of upper flapping-start of lower flapping' of the left wing rod as an example, when the left wing rod 109 is driven by the inertial load to be about to exceed the designed flapping amplitude range, the convex column at the lower end of the left wing rod 109 is contacted with the outer end flat plate of the first wing rod stop part 202, so as to drive the first wing rod stop part 202 to rotate clockwise along the first circular groove of the first support cylinder 201, further the first wing rod stop part 202 drives the first spring 206 to start to compress, because the other end of the first spring 206 is connected with the first spring connecting piece 203, when the control execution mechanism is kept motionless, the position of the first spring connecting piece 203 is kept motionless. Therefore, the first spring 206 converts the kinetic energy transmitted by the first wing rod stop part 202 into elastic potential energy, and applies resistance opposite to the movement direction of the left wing rod 109 through the first wing rod stop part 202, so as to accelerate the upward flapping ending process; after the kinetic energy of the left wing rod 109 is completely converted into the elastic potential energy of the first spring 206, the upward flapping process of the left wing rod 109 is finished, the first spring 206 releases the elastic potential energy, the downward flapping of the left wing rod 109 is accelerated on the basis of the driving force of the original transmission mechanism through the elastic force exerted on the left wing rod 109 by the first wing rod stop part 202, and the first wing rod stop part 202 returns to the initial stop position until the elastic potential energy of the first spring 206 is completely released. In the above process, on one hand, the first spring 206 accelerates the up-flapping ending process and the down-flapping starting process of the left wing rod 109, so that the turning time of the flapping wing is reduced, and the pneumatic efficiency of the flapping wing is improved; on the other hand, the first spring 206 converts the inertia work of the left wing rod 109 into elastic potential energy and then releases and applies the elastic potential energy to the left wing rod, so that the process of elastic energy storage and release of the inertia work of the left wing rod 109 is realized, the energy loss of a transmission mechanism is reduced, and meanwhile, the maximum flapping amplitude of the left flapping wing 109 can be ensured by selecting the first spring with different stiffness, and the elastic limit function is realized.

A controllable flapping amplitude bionic flapping wing micro air vehicle based on wing root elastic energy storage has the following pitching control moment generation process:

when the aircraft needs to generate a head raising pitching control moment, the left rotary steering engine 209 rotates clockwise to drive the tension rope I215 to move to the left side, the spring connecting piece I203 restrains and loosens, the spring connecting piece I203 rotates clockwise, the spring drives the wing rod stop piece I202 to rotate clockwise, so that the upper flapping limit amplitude of the left wing rod 109 is increased, the spring connecting piece III 219 rotates anticlockwise under the drive of the tension rope I215, and the spring drives the spring connecting piece III 219 to rotate anticlockwise, so that the lower flapping limit amplitude of the right wing rod 112 is reduced; the right rotary steering engine 213 anticlockwise rotates to drive the second tensioning rope 216 to move to the right, the second spring connecting piece 205 is driven by the second tensioning rope 216 to rotate clockwise, the second wing rod stop piece 204 is driven by the spring to rotate clockwise, the limit amplitude of the left wing rod 109 is reduced when slapping down, the fourth spring connecting piece 221 is restrained to loosen, the fourth wing rod stop piece 220 is driven by the spring to rotate anticlockwise, and the limit amplitude of the right wing rod 112 is increased when slapping up. The middle rotary steering engine 211 is kept still, and because the upper flapping limit amplitude of the left wing rod 109 and the right wing rod 112 is increased, the lower flapping limit amplitude is reduced, which is equivalent to that the average flapping position of the left wing rod 109 rotates anticlockwise, the average flapping position of the right wing rod 112 rotates clockwise, but the flapping amplitudes of the left wing rod and the right wing rod are approximately unchanged, the magnitude of the aerodynamic force generated by flapping motion is approximately unchanged, but the action point of the aerodynamic force moves forwards, and compared with the situation before the steering engine rotates, the head raising moment is generated. Similarly, when the aircraft needs to generate a low head pitch control moment, the left rotary steering engine 209 rotates counterclockwise, the right rotary steering engine 213 rotates clockwise, the upper flapping limit amplitude of the left wing rod 109 and the right wing rod 112 decreases, the lower flapping limit amplitude increases, which is equivalent to the average flapping position of the left wing rod 109 rotating clockwise, the average flapping position of the right wing rod 112 rotating counterclockwise, but the flapping amplitudes of the left wing rod and the right wing rod are approximately unchanged, so that the aerodynamic force generated by flapping motion is approximately unchanged, but the action point of the aerodynamic force moves backwards, and compared with the situation before the steering engine rotates, a head raising moment is generated.

A controllable flapping amplitude bionic flapping wing micro air vehicle based on wing root elastic energy storage has the following rolling control torque generation process:

when the aircraft needs to generate a right rolling control moment, the left rotary steering engine 209 rotates clockwise to drive the tension rope I215 to move leftwards, the spring connecting piece I203 restrains and loosens, the spring connecting piece I203 rotates clockwise, the spring drives the wing rod stop piece I202 to rotate clockwise, so that the upper flapping limit amplitude of the left wing rod 109 is increased, the spring connecting piece III 219 rotates anticlockwise under the drive of the tension rope I215, and the spring drives the spring connecting piece III 219 to rotate anticlockwise, so that the lower flapping limit amplitude of the right wing rod 112 is reduced; right rotary steering wheel 213 clockwise turning drives tensioning rope two 216 and moves to the left, and the restriction of spring coupling spare two 205 becomes the pine, and spring coupling spare two 205 anticlockwise turning drives wing pole stop part two 204 anticlockwise turning through the spring to the limit amplitude of clapping down of left wing pole 109 increases, and spring coupling spare four 221 drives clockwise turning down, drives four 220 clockwise turning of wing pole stop part through the spring, thereby claps the limit amplitude on right wing pole 112 and reduces. The middle rotary steering engine 211 is kept still, and because the upper and lower flapping limit amplitudes of the left wing rod 109 are increased, the upper and lower flapping limit amplitudes of the right wing rod 112 are decreased, which is equivalent to the flapping amplitude of the left wing rod 109 being increased, the flapping amplitude of the right wing rod 112 being decreased, and the average flapping positions of the left and right wing rods being unchanged, the aerodynamic force generated by the flapping motion of the left flapping wing is increased, the aerodynamic force generated by the flapping motion of the right flapping wing is decreased, but the action point of the aerodynamic force is approximately unchanged, and a right rolling moment is generated compared with that before the steering engine rotates. Similarly, when the aircraft needs to generate a left rolling moment, the left rotary steering engine 209 rotates counterclockwise, and the right rotary steering engine 213 rotates counterclockwise, so that the upper and lower flapping limit amplitudes of the left wing rod 109 are reduced, the upper and lower flapping limit amplitudes of the right wing rod 112 are increased, which is equivalent to the reduction of the flapping amplitude of the left wing rod 109, the flapping amplitude of the right wing rod 112 is increased, and the flapping average positions of the left and right wing rods are unchanged, so that the aerodynamic force generated by the flapping motion of the left flapping wing is reduced, the aerodynamic force generated by the flapping motion of the right flapping wing is increased, but the action point of the aerodynamic force is approximately unchanged, and the left rolling moment is generated before the rotation of the steering engine.

A controllable flapping amplitude bionic flapping wing micro aircraft based on wing root elastic energy storage has the following yaw control moment generation process:

when the aircraft needs to generate a left yaw control moment, the left rotary steering engine 209 and the right rotary steering engine 213 are kept still, the middle rotary steering engine 211 drives the cam 212 to rotate clockwise, two sides of the first tensioning rope 215 are simultaneously tensioned due to the change of the diameter of the cam 212, and two sides of the second tensioning rope 216 are simultaneously restrained and loosened. The first spring connecting piece 203 is driven by the first tensioning rope 215 to rotate anticlockwise, the first wing rod stop piece 202 is driven by a spring to rotate anticlockwise, so that the upward flapping limit amplitude of the left wing rod is reduced, the third spring connecting piece 219 is driven by the first tensioning rope 215 to rotate anticlockwise, the third spring stop piece 219 is driven by the spring to rotate anticlockwise, and the downward flapping limit amplitude of the right wing rod 112 is reduced; the second spring connecting piece 205 restricts and loosens, the second spring connecting piece 205 rotates anticlockwise, the second spring connecting piece 204 rotates anticlockwise through the spring, so that the left wing rod 109 beats downwards to increase in limit amplitude, the fourth spring connecting piece 221 restricts and loosens, the fourth spring connecting piece 220 rotates anticlockwise through the spring, and the right wing rod 112 beats upwards to increase in limit amplitude. Because the upper flapping limit amplitude of the left wing rod 109 is reduced, the lower flapping limit amplitude is increased, the upper flapping limit amplitude of the right wing rod 112 is increased, the lower flapping limit amplitude is reduced, which is equivalent to that the average flapping positions of the left wing rod 109 and the right wing rod 112 simultaneously rotate anticlockwise, and because the rotating points of the left wing rod and the right wing rod are not overlapped with the gravity center of the aircraft, the lateral force of the left flapping wing and the right flapping wing generates a left yawing moment. Similarly, when the aircraft needs to generate a right yaw control moment, the left rotary steering engine 209 and the right rotary steering engine 213 are kept stationary, and the middle rotary steering engine 211 drives the cam 212 to rotate counterclockwise.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A bionic flapping wing micro air vehicle with controllable flapping amplitude based on elastic energy storage of a wing root is characterized by comprising a transmission system, a control system, a lift system and a power system;

the transmission system comprises a transmission base, a supporting base, a distributed gear speed reduction group, a connecting rod and a transmission amplifying device;

the control system comprises an elastic stopping mechanism and a control executing mechanism, the elastic stopping mechanism stores inertia of the flapping wings at the flapping limit position into elastic potential energy through a spring and releases the elastic potential energy, the movement process of the flapping wings at the flapping limit position is accelerated, the flapping aerodynamic efficiency is improved, and the energy loss of a transmission system is reduced; the control executing mechanism consists of a control supporting base, a rotary steering gear, a pulley, a cam and a tensioning rope, wherein the output end of the rotary steering gear is respectively coaxially connected with the pulley or the cam and can drive the pulley or the cam to rotate forwards and backwards, so that the tensioning rope drives the elastic stopping mechanism to rotate, the limit position of the flapping wing for upward flapping or downward flapping is changed, the flapping amplitude and the flapping average position are adjusted, and pitching, rolling and yawing control moments are generated;

the flapping wings consist of a main beam, a flexible beam, a tensioning beam and a wing membrane;

the power system is a power source of the bionic flapping wing aircraft, the driving system mechanism realizes flapping motion of the flapping wings, and the power system consists of a power device, wherein the power device can be a hollow cup motor or a brushless motor.

2. The bionic flapping wing micro aircraft based on the elastic energy storage of the wing root and the controllable flapping amplitude as claimed in claim 1, wherein the wing membrane is a flexible membrane made of polyimide, the front edge and the side edge of the wing membrane are respectively wrapped into a tubular shape and then fixed by using an adhesive, the main beam and the vertical beam respectively penetrate through the tubular space formed by the front edge and the side edge of the wing membrane and can freely rotate around the tubular space, the vertical beam is overlapped under the main beam at an angle of 90 degrees, and the flexible beam is adhered to one side of the wing membrane and forms an included angle of 30 degrees with the main beam; the wing root end of the main beam is connected with a wing rod of the transmission system.

3. The bionic flapping wing micro air vehicle based on the wing root elastic energy storage is characterized in that the transmission base is used for fixing a distribution gear reduction group and a power device, the support base is used for fixing a transmission amplifying device, a control executing mechanism of a control system and a tensioning rope of a constraint control system, the distribution gear reduction group comprises a main shaft gear and a reduction group gear, the main shaft gear is arranged on an output shaft of the power device, and the reduction group gear is meshed with the main shaft gear and reduces the high-speed movement of the power device; one end of the connecting rod is connected to an eccentric hole position of the tail end speed reduction group gear, the other end of the connecting rod is coaxially connected with the transmission amplifying device through a rivet and slides smoothly in the supporting base restraining sliding chute to form a crank sliding block mechanism, and the circular motion of the distributed gear speed reduction group after speed reduction is changed into linear reciprocating sliding in a horizontal plane; the transmission amplifying device is of a rod system structure, all the component rod pieces are fixed on the mounting hole positions of the supporting base through rivets, the linear reciprocating sliding in the horizontal plane of the connecting rod is changed into the reciprocating flapping of the wing, and meanwhile, the reciprocating flapping amplitude of the wing is amplified, so that the generation of aerodynamic force is improved.

4. The bionic flapping wing micro air vehicle based on the wing root elastic energy storage is characterized in that the elastic stopping mechanism consists of a left elastic stopping mechanism and a right elastic stopping mechanism which are respectively used for restraining the limit positions of the left flapping wing and the right flapping wing; the left elastic stopping mechanism and the right elastic stopping mechanism are the same in composition and respectively consist of a supporting cylinder, a wing rod stopping piece, a spring connecting piece and a spring; the supporting cylinder is fixedly connected in a corresponding hole position of the supporting base through a rivet, and circular ring grooves are distributed on the side surface of the supporting cylinder and used for restraining the wing rod stop piece, the spring connecting piece, the spring and a tensioning rope for controlling the actuating mechanism; the outer side of the wing rod stop piece is provided with a flat plate structure for restricting the flapping limit position of the flapping wing, the inner side of the wing rod stop piece is connected with a spring, and the other end of the spring is connected with a spring connecting piece; the spring connecting piece is simultaneously connected with a tensioning rope of the control actuating mechanism, and the wing rod stop piece and the spring connecting piece can circumferentially slide around the circular groove of the supporting cylinder; when the flapping wings are close to the extreme flapping positions, the wing rod stop parts slide along the circular groove, the position of the spring connecting piece restrained by the tensioning rope keeps unchanged, the spring is compressed at the moment to realize the elastic energy storage function, and when the inertia force and the kinetic energy of the flapping wings are completely converted into the elastic potential energy of the spring, the flapping wings reach the extreme flapping positions.

5. A bionic flapping-amplitude flapping wing micro air vehicle based on wing root elastic energy storage according to any one of claims 1 to 4, wherein the wing root elastic energy storage and release processes are as follows:

6. The method for generating the pitch control moment of the bionic flapping-wing micro aircraft based on the wing root elastic energy storage according to any one of claims 1 to 4 comprises the following steps:

when the aircraft needs to generate pitching control moment, the left and right rotary steering engines rotate reversely, the tensioning ropes of the control execution system are driven to rotate reversely through the pulleys respectively, the spring connecting piece and the wing rod stop piece which are used for limiting the upward flapping on the left side rotate clockwise (or rotate anticlockwise), the spring connecting piece and the wing rod stop piece which are used for limiting the downward flapping on the left side rotate clockwise (or rotate anticlockwise), the spring connecting piece and the wing rod stop piece which are used for limiting the upward flapping on the right side rotate anticlockwise (or rotate clockwise), the spring connecting piece and the wing rod stop piece which are used for limiting the downward flapping on the right side rotate anticlockwise (or rotate clockwise), so that the upward flapping limit position and the downward flapping limit position of the flapping wing on the left side rotate clockwise (or rotate anticlockwise) simultaneously, and the upward flapping limit position and the downward flapping limit position of the flapping wing on the right side rotate anticlockwise (or rotate clockwise) simultaneously; in the process, the middle rotary steering engine is kept still, the flapping amplitudes of the left flapping wing and the right flapping wing are unchanged, the average position of the flapping angles moves forwards or backwards simultaneously, the action points of the aerodynamic force move forwards (or backwards) simultaneously under the condition that the aerodynamic force generated by flapping motion is approximately unchanged, and the raising moment (or the lowering moment) is generated before the steering engine rotates.

7. The method for generating the rolling control torque of the bionic flapping wing micro aircraft based on the wing root elastic energy storage of any one of claims 1 to 4 comprises the following steps:

when the aircraft needs to generate rolling control torque, the left and right rotary steering engines rotate in the same direction, the tensioning ropes of the control execution system are driven to rotate in the same direction through the pulleys respectively, the left side limits the clockwise rotation (or anticlockwise rotation) of the spring connecting piece and the wing rod stop piece of the upper flapping, the left side limits the anticlockwise rotation (or clockwise rotation) of the spring connecting piece and the wing rod stop piece of the lower flapping, the right side limits the clockwise rotation (or anticlockwise rotation) of the spring connecting piece and the wing rod stop piece of the upper flapping, the right side limits the anticlockwise rotation (or clockwise rotation) of the spring connecting piece and the wing rod stop piece of the lower flapping, so that the upper flapping limit positions of the left flapping wing and the right flapping wing rotate clockwise (or anticlockwise rotation) simultaneously, and the lower flapping limit positions of the left flapping wing and the right flapping wing rotate anticlockwise (or clockwise rotation) simultaneously; in the process, the rotary steering engine is kept still, the flapping amplitude of the left flapping wing is increased (or reduced), the flapping amplitude of the right flapping wing is reduced (or increased), and the flapping average position of the left wing rod and the right wing rod is unchanged, so that the aerodynamic force generated by the flapping motion of the left flapping wing is increased (or reduced), the aerodynamic force generated by the flapping motion of the right flapping wing is reduced (or increased), and compared with the steering engine before rotation, the right rolling moment (or the left rolling moment) is generated.

8. The method for generating the controllable flapping amplitude bionic flapping wing micro air vehicle yaw control moment based on the wing root elastic energy storage of any one of claims 1 to 4 comprises the following steps:

when the aircraft needs to generate yaw control moment, the left and right rotary steering engines are kept still, the middle rotary steering engine drives the cam to rotate clockwise (or anticlockwise), and due to the change of the diameter of the cam, one side of the tensioning rope on two sides of the cam is tensioned, and the other side of the tensioning rope is loosened; the spring connecting piece and the wing rod stop piece which limit the upward flapping on the left side are driven to rotate anticlockwise (or rotate clockwise), the spring connecting piece and the wing rod stop piece which limit the downward flapping on the left side are driven to rotate clockwise (or rotate anticlockwise), the spring connecting piece and the wing rod stop piece which limit the upward flapping on the right side are driven to rotate clockwise (or rotate anticlockwise), and the spring connecting piece and the wing rod stop piece which limit the downward flapping on the right side are driven to rotate anticlockwise (or rotate clockwise), so that the upward flapping limit position of the flapping wing on the left side and the downward flapping limit position of the flapping wing on the right side simultaneously rotate anticlockwise (or rotate clockwise), and the downward flapping limit position of the flapping wing on the left side and the upward flapping limit position of the flapping wing on the right side simultaneously rotate clockwise (or rotate anticlockwise); the flapping amplitude of the left flapping wing and the flapping amplitude of the right flapping wing are unchanged, and the average flapping positions of the left flapping wing and the right flapping wing simultaneously rotate anticlockwise (or clockwise), so that the lateral force of the left flapping wing and the right flapping wing generates a left yaw moment (or right yaw) because the rotating points of the left flapping wing and the right flapping wing are not coincident with the gravity center of the aircraft.