CN109050912B

CN109050912B - Flapping wing mechanism combining electromagnetic drive and rope transmission

Info

Publication number: CN109050912B
Application number: CN201810921245.6A
Authority: CN
Inventors: 吴江浩; 贾媛; 李港; 张梓箫; 张艳来
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2018-08-14
Filing date: 2018-08-14
Publication date: 2021-07-16
Anticipated expiration: 2038-08-14
Also published as: CN109050912A

Abstract

The application discloses flapping wing mechanism combining electromagnetic driving and rope transmission, which comprises a rope transmission mechanism, an electromagnetic driving mechanism and a pair of flapping wings. Through the technical scheme of the invention, energy absorption and storage can be buffered and stored in the flapping wing movement process, the effects of vibration reduction and energy consumption reduction can be realized, meanwhile, the movement can be accurately controlled, and the movement instability and asymmetry caused by the shaking of the eccentric gear in the traditional design can be avoided.

Description

Flapping wing mechanism combining electromagnetic drive and rope transmission

Technical Field

The present invention relates to the field of micro-aircraft and in particular, but not exclusively, to an electromagnetically driven flapping wing mechanism in combination with a rope drive.

Background

With the continuous maturation of the traditional aircraft design technology and the great progress of the microelectronic technology since the nineties of the twentieth century, the concept of micro aircraft has been proposed and its rapid development has been promoted. The micro aircraft has small volume, light weight and strong maneuverability, has wide application prospect in the aspects of national safety and national economic construction, and can be used for investigation, exploration, assistance in rescue and the like in complex environments. Meanwhile, with the continuous exploration of the flying principle of natural organisms (such as insects), the bionic design is more and more applied to the field of micro aircrafts, and various bionic flapping wing micro aircrafts simulating the flying of insects appear.

The flapping motion of the wings of the current bionic flapping wing micro air vehicle mostly adopts a design scheme of 'motor-gear reduction group-crank connecting rod', and the high-speed rotating motion output by the motor drives the crank connecting rod mechanism after being reduced by the gear reduction group, so as to drive the wings to flap in a reciprocating manner. In the scheme, the friction resistance between the gears in the gear reduction group is large, the energy loss is high, and meanwhile, as the miniature aircraft is light in weight, small in size, limited in energy of a carried power supply and limited by the low energy density of the current battery, the high energy loss of the mechanism is obviously unfavorable for improving the endurance performance of the aircraft. In order to solve the problems, a design scheme of an electromagnetic driving connecting rod and a design scheme of motor driving rope transmission are provided, wherein in the scheme of the electromagnetic driving connecting rod, a rod piece structure is often in a bad working state of friction and high-speed rotation, the structure is easy to break, and the reliability is poor; in the "motor drive cord drive" scheme, an eccentric gear is present, although the high speed rotating gear reduction group is eliminated. When the mechanism is assembled, a certain gap usually exists between the eccentric gear shafts, and moment in a vertical plane is acted on the eccentric gear when the mechanism is executed, and the eccentric gear and the gear frequently shake under the combined action of the eccentric gear and the gear, so that the flapping motion of the output wing is not symmetrical left and right.

Disclosure of Invention

In order to solve the defects that the energy loss of the design scheme of the traditional 'motor-gear reduction set-crank connecting rod' is high, the rod piece friction of the design scheme of the 'electromagnetic drive connecting rod mechanism' causes the rod piece to be easily broken, and the eccentric gear of the design scheme of the 'motor drive rope transmission' shakes, the invention provides the flapping wing mechanism combining electromagnetic drive and rope transmission, which reduces the friction loss among mechanism parts while ensuring the stability and symmetry of flapping wing flapping motion, and simultaneously reduces the mechanism vibration and improves the energy utilization efficiency by utilizing energy storage parts such as springs, drive ropes and the like.

The flapping wing mechanism combining electromagnetic driving and rope driving is characterized by comprising a rope driving mechanism, an electromagnetic driving mechanism and a pair of flapping wings, wherein the rope driving mechanism comprises a rack, a first rocker arm and a second rocker arm which are symmetrically arranged on two sides of the central axis of the rack, a vertical rod arranged in a rectangular groove of the rack, a cross beam and three thin ropes which are arranged on the first rocker arm and the second rocker arm and used for restraining the horizontal displacement of the first rocker arm and the second rocker arm, the vertical rod can slide in the rectangular groove of the rack in a reciprocating manner, a first positioning hole and a second positioning hole are formed in the vertical rod, a first mounting hole, a second mounting hole, a third mounting hole and a fourth mounting hole are formed in the first rocker arm and the second rocker arm respectively, the electromagnetic driving mechanism comprises a base, and coils distributed on the central axis of the base from left to right, The flapping wing structure comprises a spring, a magnet and a slider, wherein the bottom end of a vertical rod is fixedly connected with the slider, the vertical rod can reciprocate in a rectangular groove of a rack, the pair of flapping wings respectively comprise a main beam, three auxiliary beams and a wing membrane, one end of the main beam is connected with one ends of the three auxiliary beams, the other end of the main beam is respectively installed in a fourth installation hole of the first rocker arm and a fourth installation hole of the second rocker arm, and every two adjacent auxiliary beams are 15-20 degrees and are adhered to the wing membrane.

Preferably, the rack is of a bilateral symmetry structure, the bilateral symmetry structure is provided with a first threaded hole and a second threaded hole, the bottom end of the first rocker arm is mounted in the first threaded hole, the bottom end of the second rocker arm is mounted in the second threaded hole, and the first rocker arm and the second rocker arm can rotate horizontally.

Preferably, two ends of the cross beam are respectively fixed with the first rocker arm and the second rocker arm through a first mounting hole of the first rocker arm and a first mounting hole of the second rocker arm.

Preferably, the three strings include a first transmission string, a second transmission string and a limiting string, wherein the first transmission string is connected with the first positioning hole of the vertical rod and the third mounting hole of the first rocker arm, the second transmission string is connected with the second positioning hole of the vertical rod and the third mounting hole of the second rocker arm, and the limiting string is connected with the second mounting hole of the first rocker arm and the second mounting hole of the second rocker arm.

Preferably, a slide rail for enabling the magnet and the slide block to slide linearly is arranged on the central axis of the base, the slide block is connected in the slide rail through rivets, and the stroke of the slide block is 20mm-22 mm.

Preferably, the main beam and the auxiliary beams are made of carbon fiber rods, and the wing membrane is a polyethylene film.

Preferably, the base is integrally made of a resin material or a polylactic acid material through 3D printing.

The invention has the beneficial effects that:

1. the flapping wing energy absorber has the advantages that the springs and the transmission ropes are utilized, energy can be absorbed and stored in a buffering mode in the flapping wing motion process, mechanical vibration and energy loss caused by friction and collision of mechanical parts in the traditional design are avoided, and the effects of vibration reduction and energy consumption reduction are achieved.

2. The electromagnetic drive is utilized to realize the accurate control of the movement, and the movement instability and asymmetry caused by the shaking of the eccentric gear in the traditional design are avoided.

Drawings

FIG. 1 is a schematic view of an electromagnetic drive and rope drive combined flapping wing mechanism of the present invention;

FIG. 2 is a schematic view of a cord drive mechanism;

FIG. 3 is a schematic view of an electromagnetic drive mechanism;

FIG. 4 is a schematic structural view of a frame;

FIG. 5 is a schematic structural view of the first rocker arm;

FIG. 6 is a schematic structural view of a second rocker arm;

FIG. 7 is a schematic view of the structure of the vertical rod;

FIG. 8 is a schematic structural view of a cross beam;

FIG. 9 is a schematic structural view of a base;

FIG. 10 is a schematic view of a slider configuration;

fig. 11 is a schematic structural view of the flapping wings.

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. The present invention will be described in further detail with reference to the accompanying drawings and examples.

Fig. 1 is an overall schematic view of an electromagnetically driven rope-drive flapping wing mechanism of the present invention, fig. 2 shows an exemplary embodiment of a rope-drive mechanism, fig. 3 shows an exemplary embodiment of an electromagnetically driven mechanism, and an electromagnetically driven rope-drive flapping wing mechanism is shown, which includes a rope-drive mechanism 10, an electromagnetically driven mechanism 20, and a pair of flapping

wings

30 and 40. The rope transmission mechanism 10 includes a frame 101, a first swing arm 102 and a second swing arm 103 symmetrically disposed on two sides of a central axis of the frame 101, a vertical rod 104 disposed in a rectangular groove 1012 of the frame 101, a cross beam 105 and three

strings

106, 107, 108 disposed on the first swing arm 102 and the second swing arm 103 and used for restricting horizontal displacement of the first swing arm 102 and the second swing arm 103, wherein the vertical rod 104 can reciprocate in the rectangular groove 1012 of the frame 101, the vertical rod 104 is provided with a first positioning hole 1041 and a second positioning hole 1042, the first swing arm 102 and the second swing arm 103 are respectively provided with a

first mounting hole

1021, 1031, a

second mounting hole

1022, 1032, a

third mounting hole

1023, 1033, and a

fourth mounting hole

1024, 1034. The electromagnetic drive mechanism 20 includes a base 201, a coil 202, a spring 203, a magnet 204, and a slider 205 arranged on the central axis of the base 201 from left to right. The bottom end of the vertical rod 104 is fixedly connected with the sliding block 205, and the vertical rod 104 can slide in a reciprocating manner in the rectangular groove 1012 of the frame 101. The pair of flapping

wings

30 and 40 respectively comprises a main beam 301, three

auxiliary beams

302, 303 and 304 and a wing membrane 305, one end of the main beam 301 is connected with one end of the three

auxiliary beams

302, 303 and 304, the other end of the main beam 301 is respectively arranged in a fourth mounting hole 1021 of the first rocker arm 102 and a fourth mounting hole 1034 of the second rocker arm 103, and every two adjacent

auxiliary beams

302, 303 and 304 are adhered to the wing membrane 305 at an angle of 15-20 degrees.

Fig. 4 shows an exemplary embodiment of the frame, the frame 101 has a left-right symmetrical structure, the left-right symmetrical structure is provided with a first screw hole 1011 and a second screw hole 1013, the bottom end of the first swing arm 102 is installed in the first screw hole 1011, the bottom end of the second swing arm 103 is installed in the second screw hole 1013, and the first swing arm 102 and the second swing arm 103 can rotate horizontally.

Fig. 5 and 6 illustrate an exemplary embodiment of a first rocker arm and a second rocker arm.

Fig. 7 shows an exemplary embodiment of a vertical bar, and both ends of the cross beam 105 are fixed to the first swing arm 102 and the second swing arm 103 through the first mounting hole 1021 of the first swing arm 102 and the first mounting hole 1031 of the second swing arm 103, respectively.

Fig. 8 shows an exemplary embodiment of the cross beam, and in conjunction with fig. 2, fig. 5, fig. 6 and fig. 8, the three strings include a first driving string 106, a second driving string 107 and a limiting string 108, wherein the first driving string 106 connects the first positioning hole 1041 of the vertical rod 104 and the third mounting hole 1023 of the first swing arm 102, the second driving string 107 connects the second positioning hole 1042 of the vertical rod 104 and the third mounting hole 1033 of the second swing arm 103, and the limiting string 108 connects the second mounting hole 1022 of the first swing arm 102 and the second mounting hole 1032 of the second swing arm 103.

Fig. 9 and 10 show an exemplary embodiment of a base and a slider, respectively, a slide rail for enabling the magnet 204 and the slider 205 to slide linearly is arranged on a central axis of the base 201, the slider 205 is riveted into the slide rail, and a stroke of the slider 205 is 20mm to 22 mm. In some embodiments, the base 201 is integrally made of a resin material or a polylactic acid material through 3D printing.

Fig. 11 shows an exemplary embodiment of an ornithopter, in some embodiments one main beam 301 and three

auxiliary beams

302, 303, 304 made of carbon fiber rods, the wing membrane 305 being a polyethylene film.

The operation of the flapping wing mechanism combining electromagnetic drive and rope transmission according to the present invention will be described with reference to fig. 1-9, wherein the following directional expressions refer to the left and right directions in the direction shown in fig. 3, and the viewing angles of the expressions referring to the positive and negative limit positions and the clockwise and counterclockwise directions are top-view viewing angles, i.e., viewing angles from top to bottom in fig. 1. Before the coil 202 is powered on at the initial moment, the spring 203 is in a natural state, the slide block 205 and the vertical rod 104 are positioned at the left limit position, and the flapping

wings

30 and 40 and the first rocker arm 102 and the second rocker arm 103 are positioned at the positive limit position. The coil 202 is connected with sine alternating current, firstly, the flapping frequency of the flapping wing is determined according to the requirement of the mission load of the aircraft on the lift force by combining the geometry and the motion constraint of the flapping wing, the frequency of the sine alternating current is consistent with the flapping frequency of the flapping

wings

30 and 40, and secondly, the magnetic force generated by the coil 202 can just enable the sliding block 205 to do simple harmonic vibration in the sliding rail of the base 201, and accordingly, the amplitude of the sine alternating current is calculated. In the first half of the current alternating period, the N, S magnetic field generated by the coil 202 is just opposite to the magnetic pole of the magnet 204, at this time, the coil 202 generates repulsive force to the magnet 204 to push the slider 205 to move rightwards, meanwhile, the vertical rod 104 moves rightwards along with the slider 205, the vertical rod 104 drives the transmission rope 106 to generate pulling force to the first rocker 102 to drive the first rocker 102 and the flapping wing 30 thereon to flap anticlockwise, the limiting rope 108 is tightened to drive the second rocker 103 and the flapping wing 40 thereon to flap clockwise; when the sliding block 205 moves to the right limit position, the first rocker arm 102 and the second rocker arm 103 also move to the negative limit position, the limiting rope 108 is tightened to limit the movement of the first rocker arm 102 and the second rocker arm 103, at the moment, the alternating current enters the lower half period of the current alternating period, the alternating current changes the current direction, the magnetic deformation of the coil 202 is consistent with the magnetic pole distribution of the magnet 204, the coil 202 generates attraction force on the magnet 204, meanwhile, the spring 203 generates tensile deformation to the left, the slider 205 is driven to move leftwards by the electromagnetic attraction force and the tensile force of the spring 203, the vertical rod 104 moves leftwards along with the sliding block 205, the vertical rod 104 drives the transmission rope 107 to generate tensile force on the second rocker arm 103, the second rocker arm 103 and the flapping wing 40 thereon flap anticlockwise, the limiting rope 108 is tightened to drive the first rocker arm 102 and the flapping wing 30 thereon flap clockwise, and when the sliding block 205 moves to the left limit position, one current alternation cycle ends with the first 102 and second 103 rocker arms returning to the positive limit position and the check rope 108 limiting the flapping motion of the first 102 and second 103 rocker arms. Thus, by periodically changing the direction of the coil 202 current, a reciprocating flapping motion of the flapping

wings

30, 40 is achieved.

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 flapping wing mechanism combining electromagnetic driving and rope transmission is characterized by comprising a rope transmission mechanism, an electromagnetic driving mechanism and a pair of flapping wings, wherein,

the rope transmission mechanism comprises a rack, a first rocker arm and a second rocker arm which are symmetrically arranged on two sides of the central axis of the rack, a vertical rod arranged in a rectangular groove of the rack, and a cross beam and three thin ropes which are arranged on the first rocker arm and the second rocker arm and used for restricting the horizontal displacement of the first rocker arm and the second rocker arm, wherein the vertical rod can reciprocate in the rectangular groove of the rack, a first positioning hole and a second positioning hole are formed in the vertical rod, and a first mounting hole, a second mounting hole, a third mounting hole and a fourth mounting hole are respectively formed in the first rocker arm and the second rocker arm;

the three thin ropes comprise a first transmission rope, a second transmission rope and a limiting rope, wherein the first transmission rope is connected with a first positioning hole of the vertical rod and a third mounting hole of the first rocker arm, the second transmission rope is connected with a second positioning hole of the vertical rod and a third mounting hole of the second rocker arm, and the limiting rope is connected with a second mounting hole of the first rocker arm and a second mounting hole of the second rocker arm;

the electromagnetic driving mechanism comprises a base, a coil, a spring, a magnet and a sliding block, wherein the coil, the spring, the magnet and the sliding block are arranged on the central axis of the base from left to right; a slide rail used for enabling the magnet and the slide block to slide linearly is arranged on the central axis of the base, the slide block is connected in the slide rail through rivets, and the stroke of the slide block is 20mm-22 mm;

the pair of flapping wings respectively comprises a main beam, three auxiliary beams and a wing membrane, one end of the main beam is connected with one end of each of the three auxiliary beams, the other end of the main beam is respectively installed in the fourth installation hole of the first rocker arm and the fourth installation hole of the second rocker arm, and every two adjacent auxiliary beams are adhered to the wing membrane at an angle of 15-20 degrees.

2. The flapping wing mechanism of claim 1, wherein the frame has a bilateral symmetry structure, and has a first threaded hole and a second threaded hole, the first threaded hole is provided at a bottom end of the first rocker arm, the second threaded hole is provided at a bottom end of the second rocker arm, and the first rocker arm and the second rocker arm can rotate horizontally.

3. The flapping wing mechanism of claim 1 or 2, wherein the two ends of the cross beam are fixed to the first rocker arm and the second rocker arm through the first mounting hole of the first rocker arm and the first mounting hole of the second rocker arm, respectively.

4. An electromagnetic drive and rope drive combined flapping wing mechanism according to claim 1 or 2, wherein the main beam and the three auxiliary beams are made of carbon fiber rods, and the wing membrane is a polyethylene film.

5. An electromagnetic drive and rope drive combined flapping wing mechanism according to claim 1 or 2, wherein the base is integrally made of resin material or polylactic acid material by 3D printing.