Foldable ornithopter

Abstract

The foldable ornithopter comprises an ornithopter body and wings installed on the two sides of the ornithopter body, each wing comprises a flexible folding area, a support and a push rod, one end of each flexible folding area is fixed to the corresponding support, one side of each flexible folding area is connected with the side edge of the corresponding push rod, and the other side of each flexible folding area is connected with the corresponding push rod. And one end of the push rod is connected with a rotating mechanism mounted on the bracket. And when the push rod rotates, the flexible folding area is compressed and folded, so that the flexible folding area is extruded into a line. The high-folding-degree folding ornithopter has the beneficial effects that the high-folding-degree folding of the ornithopter is realized by imitating a folding mode and a folding sequence of a scissors worm. And the memory metal is innovatively adopted as a ring of the wing folding mechanism, so that the problems of low folding rate, high technical threshold and the like of the folding wing of the ornithopter are solved. The device can be widely applied to the fields of military reconnaissance, field environment exploration, long-distance transportation, battlefield reconnaissance, agricultural detection, search and rescue and the like.

Description

Technical Field

[0001] The invention belongs to the field of flapping-wing aircraft, and in particular relates to a foldable flapping-wing aircraft. Background Art

[0002] A flapping-wing aircraft is a machine that can fly by flapping its wings like a bird. Currently, existing flapping-wing aircraft have the problem that the size of the wing area and the strength of the wing cannot be achieved at the same time. If the strength is guaranteed, the wing area will be relatively small, which will result in small lift of the machine and less equipment on board; if the wing area is increased to increase lift, the wing is prone to damage during transportation. This makes it difficult for existing flapping-wing aircraft to adapt to long-distance transportation, bumpy transportation routes or large load operations. Summary of the invention

[0003] In view of this, the invention aims to provide a foldable flapping-wing aircraft with wings that can be automatically unfolded and retracted with a high degree of foldability.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] A foldable flapping-wing aircraft comprises a fuselage and wings mounted on both sides of the fuselage, wherein the wings comprise a flexible folding area, a bracket and a push rod, wherein one end of the flexible folding area is fixed to the bracket, one side of the flexible folding area is connected to the side edge of the push rod, and one end of the push rod is connected to a rotating mechanism mounted on the bracket. (When the push rod rotates, the flexible folding area is compressed and folded, so that the flexible folding area is squeezed into a line)

[0006] Furthermore, the rotating mechanism includes a fan-shaped folding motor fixed on the bracket, the fan-shaped folding motor drives a gear set to move, and the gear set drives the push rod to rotate.

[0007] Furthermore, the fan-shaped folding motor drives the first bevel gear, the first bevel gear drives the second gear, the second gear drives the third gear, and one end of the push rod is fixed to the rotating shaft or gear teeth of the third gear.

[0008] Furthermore, the bottom surface or the top surface of the flexible folding area is pasted with memory metal, the flexible folding area is planned with folds (according to the folds of a paper folding fan), the original shape of the memory metal at the folds has an angle, and the original shape angles of the memory metals at adjacent folds are peaks and valleys that alternate with each other;

[0009] The memory metal is provided with a heating wire.

[0010] Furthermore, the heating wire is connected to the heater on the body. (After the memory metal is heated (heated by the heating wire), the memory metal returns to its original shape, and the flexible folding area is deformed together, and an angle is generated at the planned folding line. When the push rod rotates, the flexible folding area can be driven to fold like a paper folding fan.)

[0011] Furthermore, the original shape angle of the memory metal is 120°.

[0012] Furthermore, the bracket is composed of a lower cover plate and an upper cover plate. By flipping the folding structure, the bracket can be folded along the middle portion, so that the flexible folding area that has already formed a line is also folded in half.

[0013] Furthermore, the flip folding structure includes a flip motor, a pull wire and a torsion spring, a bobbin is installed on the output shaft of the flip motor, one end of the pull wire is connected to the bobbin, the flip motor is fixed on a cover plate, and the other end of the pull wire is fixed to another cover plate (the pull wire can be retracted and released by controlling the direction of the output shaft of the flip motor), and the torsion spring is installed at the folding part of the bracket;

[0014] When the line is reeled in, the torsion spring is compressed and the cover plate is folded, thereby realizing the folding of the entire wing; when the line is released, under the action of the restoring force of the torsion spring, the cover plate is laid flat, and the flexible folding area is also laid flat.

[0015] Furthermore, the flexible folding area is 3D printed with TPU material, and the fuselage is a carbon rod; the flexible folding area is fan-shaped, semicircular, or scissor-worm wing-shaped.

[0016] Furthermore, it also includes a servo steering engine, a controller, a power supply, and a receiver, which are all fixed to the fuselage through 3D printed connectors, and the heater is directly fixed to the fuselage (to avoid melting of the 3D printed connector during heating), and the rocker arm of the servo steering engine is connected to the bracket of the wing;

[0017] The fuselage is connected to the wing brackets through carbon tubes. (In order to carry a variety of equipment and take into account the problem of easy carrying during long-distance transportation, the fuselage adopts a lightweight design structure.)

[0018] The advantages and positive effects of the invention are: compared with traditional flapping-wing aircraft, this scheme can achieve maximum space saving and has the function of automatic unfolding and retraction. The present invention imitates the folding method and sequence of the scissor worm to achieve high folding degree of flapping-wing aircraft. And the innovative use of memory metal as a part of the wing folding mechanism solves the problems of low folding rate and high technical threshold of flapping-wing aircraft. It can be widely used in military reconnaissance, field environment exploration, long-distance transportation, battlefield reconnaissance, agricultural detection and search and rescue. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a bottom view of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the wing part of the present invention;

[0022] Figure 3 It is a side view of the present invention.

[0023] In the figure:

[0024] 1. Fuselage 2. Wings 3. Flexible folding area 4. Bracket

[0025] 5. Push rod 6. Fan-shaped folding motor 7. Gear set 8. Crease

[0026] 9. Heating wire 10. Lower cover 11. Upper cover 12. Folding motor

[0027] 13. Pull wire 14. Torsion spring 15. Spool 16. Carbon tube DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the invention to clearly and completely describe the technical solutions in the embodiments of the invention. Obviously, the described embodiments are only part of the embodiments of the invention, not all of them. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention. In the absence of conflict, the embodiments in the invention and the features in the embodiments can be combined with each other.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the invention is described in detail with reference to the schematic diagram. When describing the embodiments of the invention, for the sake of convenience, the cross-sectional diagrams showing the structure of the device will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the invention. In addition, in actual production, the three-dimensional dimensions of length, width and height should be included.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0032] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0033] like Figure 1 , Figure 2 and Figure 3 As shown, the invention comprises a fuselage 1 and wings 2 installed on both sides of the fuselage, the wings 2 comprising a flexible folding area 3, a bracket 4 and a push rod 5, one end of the flexible folding area 3 is fixed on the bracket 4, one side of the flexible folding area 3 is connected to the side of the push rod 5, and one end of the push rod 5 is connected to a rotating mechanism installed on the bracket 4. When the push rod rotates, the flexible folding area is compressed and folded, so that the flexible folding area is squeezed into a line.

[0034] The rotating mechanism comprises a fan-shaped folding motor 6 fixed on the bracket, the fan-shaped folding motor drives a gear set 7 to move, and the gear set 7 drives the push rod 5 to rotate.

[0035] The gear set 7 includes a first bevel gear, a second gear and a third gear. The fan-shaped folding motor 6 drives the first bevel gear, the first bevel gear drives the second gear, the second gear drives the third gear, and one end of the push rod 5 is fixed to the rotating shaft or gear teeth of the third gear.

[0036] The bottom or top surface of the flexible folding area 3 is pasted with memory metal, and the flexible folding area is planned with a fold 8 (according to the fold of a paper folding fan), and the original shape of the memory metal at the fold 8 has an angle of 120°, and the original shape angles of the memory metals at adjacent folds 8 are alternating peaks and valleys;

[0037] A heating wire 9 is arranged on the memory metal.

[0038] Furthermore, the heating wire 9 is connected to the heater on the body 1. After the memory metal is heated (heated by the heating wire), the memory metal restores its original shape, and deforms the flexible folding area 3 together, and an angle is generated at the planned folding line 8. When the push rod 5 rotates, the flexible folding area 3 can be driven to fold like a paper folding fan.

[0039] The bracket is composed of a lower cover plate 10 and an upper cover plate 11. By flipping the folding structure, the bracket can be folded along the middle so that the lower cover plate 10 and the upper cover plate 11 overlap, and the flexible folding area 3 that has been formed into a line is also folded in half.

[0040] The flip folding structure includes a flip motor 12, a pull wire 13 and a torsion spring 14. A bobbin 15 is installed on the output shaft of the flip motor 12. One end of the pull wire 13 is connected to the bobbin 15. The flip motor 12 is fixed to a cover plate, and the other end of the pull wire 13 is fixed to another cover plate. The pull wire 13 can be retracted and released by controlling the steering direction of the output shaft of the flip motor 12. The torsion spring 14 is installed at the folding part of the bracket.

[0041] When the line is collected, the torsion spring 14 is compressed and the cover plate is folded, thereby realizing the folding of the entire wing; when the line is released, under the action of the restoring force of the torsion spring 14, the cover plate is laid flat, and the flexible folding area 3 is also laid flat.

[0042] The flexible folding area is 3D printed with TPU material, and the fuselage is a carbon rod; the flexible folding area is fan-shaped, semicircular, or scissor-worm wing-shaped.

[0043] The present invention also includes a servo steering engine, a controller, a power supply, and a receiver, which are all fixed to the fuselage through 3D printed connectors, and the heater is directly fixed to the fuselage (to avoid melting of the 3D printed connector during heating), and the rocker arm of the servo steering engine is connected to the bracket of the wing;

[0044] The fuselage is connected to the bracket of the wing through a carbon tube 16. In order to carry a variety of equipment and take into account the problem of easy carrying during long-distance transportation, the fuselage adopts a lightweight design structure. The wingspan of the invention is 340 mm and the length of the whole machine is 300 mm.

[0045] The servo steering engine driving method of the present invention is as follows:

[0046] The servo servo is fixed on the fuselage. The rocker arm of the servo servo is connected to the wing. The power supply is 5V. The controller controls the angle of the motor inside the servo servo through a PWM wave of a specified frequency (the duty cycle of PWM can determine the angle of the motor). Two servo servos are selected as the driving device. First, TIM2 and GPIOA clocks are turned on to initialize the GPIO of the servo servo. The two servo servos use pins 1 and 2, and select multiplexed push-pull output. Then the counter mode selects up counting, the ARR calculation cycle is given, the PSC is given to set the pre-divider, and the output comparison mode selects PWM comparison mode 1. CCR and ARR jointly determine the duty cycle, and the duty cycle Duty=CCR / (ARR+1). After setting up the servo servo, consider using the A8S receiver to realize the connection between the remote control and the controller. The A8S receiver is connected through the SBUS protocol to match the remote control. The controller processes the received data. Similarly, a series of initializations are performed on the SBUS protocol in the controller, including GPIO initialization, NVIC configuration, and USART initialization. First, the values ​​sent by each channel are converted and processed. Start interrupt reception, and start receiving after judging the end mark. After receiving 26 data, it will automatically clear and prepare for the next reception. Limit the received data. In order to make the flight as normal as possible, let the servo motor flap according to the sine function. Use channel 1 to control left and right turns. Through linear conversion, let 595 to 1595 correspond to -10 to 10, so as to produce a difference in the amplitude on both sides, and then turn. Channel 2 controls the state of the wings at the beginning. Channel 3 controls the amplitude size. The amplitude is large during takeoff. After takeoff, the amplitude is stabilized so that the flapping-wing aircraft can fly normally. The amplitude can be set to 0 when landing. Channel 4 can change the frequency. Increase the frequency during takeoff and reduce the frequency appropriately for stable flight after takeoff. .

[0047] Heater temperature control method: The memory metal is folded along a fixed path, which requires temperature PID control: the controller outputs a signal to the heater, and the power supply supplies power to the heater to heat it and control the folding of the memory metal.

[0048] Set a target heating temperature for the memory metal, set as SV. From the start of the system operation, collect the temperature in the current environment at regular intervals, set as X. Compare the current temperature with the set target temperature to obtain the deviation E, E = SV-X. Comparing E with the target heating temperature will result in three situations: E>0; E = 0; E < 0. When E>0, the output power of the heating wire needs to be increased, and when E < 0, the output power of the heating wire needs to be reduced. The difference E is obtained by subtracting the user-set value SV from the collected ambient temperature data. Due to continuous temperature collection, there will be a series of difference samples, set as En, and these differences are accumulated and set as S, S = E1 + E2 + E2 +...... + En. Use integration to eliminate steady-state errors. S is the cumulative sum of errors. When the system is in a steady state, that is, the temperature reaches the set temperature, E = 0, then the proportional control output Pout and the differential control output Pout are both 0, and only the integral control output Iout is at this time To maintain system stability, the difference Dn between the two most recent differences can be expressed as En-En-1. Dn also has three conditions: Dn>0; Dn=0; Dn<0. Dn can reflect the state change trend of the temperature of the two most recent samples. The larger the absolute value of Dn, the greater the temperature change rate. It can be seen that Dn has the function of suppressing temperature changes and making it stable. The three values ​​of P, I, and D are adjusted to adjust the system output to improve the system response effect. The PID adjustment signal is transmitted to the heater in the form of a PWM wave to heat the memory metal, and the signal is fed back to the PID for a new cycle.

[0049] The controller of the present invention adopts a stm32F103C8T6 single-chip microcomputer to control the rotation of the servo steering gear, thereby driving the wing to flap up and down, controlling the temperature change of the heater, transferring heat to the memory metal through the heating wire, changing the shape of the memory metal, and the memory metal is bonded to the flexible folding area through glue, thereby driving the flexible folding area to fold from 180° to 120°, and then the fan-shaped folding is achieved through the gear set and the push rod, and the entire wing folding is completed through the folding motor, the bobbin, the pull wire, and the torsion spring. After folding, all the driving devices on the wing are tightened inside the wing folding, keeping the appearance of the aircraft neat and tidy, which is conducive to its concealment, camouflage and safe transportation. .

[0050] The flexible folding area uses TPU film with memory metal bonded on it. The memory metal is heated to achieve initial folding of the flexible folding area along the fan-shaped texture, and then the wings are fully unfolded and folded through motors, gears, torsion springs and shafts.

[0051] The present invention fills the gap in the folding wing of flapping-wing aircraft, utilizes the folding method and sequence of scissor worms, realizes the innovation and realization of the high folding degree folding method of flapping-wing aircraft, and innovatively uses memory metal as a link of the wing folding mechanism, solving the problems of low folding rate and high technical threshold of flapping-wing aircraft folding wings. It can realize longitudinal fan-type folding, annular folding folding, and fan-type double folding, with simple materials and high economic benefits.

[0052] The present invention can not only meet the requirements of easy transportation and carrying large loads, but also cleverly utilizes the principle of bionics, imitates the shape, pattern and sequence of the folding wings of scissor worms, and achieves a folding rate of 10 times the wing area. Such a design can be widely used in special environments such as military reconnaissance, field environment exploration, agricultural detection, search and rescue, long-distance transportation, and carrying a lot of equipment. Secondly, the design of combining memory metal with gear structure provides a new solution for the folding method of flapping-wing aircraft, which is convenient for the improvement of flapping-wing aircraft folding wings in the future and improves its stability and economy.

[0053] The above is a detailed description of the embodiments of the present invention, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A foldable flapping-wing aircraft, comprising a fuselage and wings mounted on both sides of the fuselage, characterized in that: The wing includes a flexible folding area, a bracket and a push rod, one end of the flexible folding area is fixed on the bracket, one side of the flexible folding area is connected to the side of the push rod, and one end of the push rod is connected to a rotating mechanism installed on the bracket.

2. The foldable flapping-wing aircraft according to claim 1, characterized in that: The rotating mechanism comprises a fan-shaped folding motor fixed on the bracket, the fan-shaped folding motor drives a gear set to move, and the gear set drives the push rod to rotate.

3. The foldable flapping-wing aircraft according to claim 2, characterized in that: The fan-shaped folding motor drives the first bevel gear, the first bevel gear drives the second gear, the second gear drives the third gear, and one end of the push rod is fixed to the rotating shaft or gear teeth of the third gear.

4. The foldable flapping-wing aircraft according to claim 1, characterized in that: The bottom surface or the top surface of the flexible folding area is pasted with memory metal, and the flexible folding area is planned with creases. The original shape of the memory metal at the creases has an angle, and the original shape angles of the memory metals at adjacent creases are peaks and valleys that alternate with each other; The memory metal is provided with a heating wire.

5. The foldable flapping-wing aircraft according to claim 4, characterized in that: The heating wire is connected to the heater on the fuselage.

6. The foldable flapping-wing aircraft according to claim 4, characterized in that: The original shape angle of the memory metal is 120°.

7. The foldable flapping-wing aircraft according to claim 1, characterized in that: The bracket is composed of a lower cover plate and an upper cover plate. By flipping the folding structure, the bracket can be folded along the middle, so that the flexible folding area that has been formed into a line is also folded in half.

8. The foldable flapping-wing aircraft according to claim 7, characterized in that: The flipping and folding structure includes a flipping motor, a pull wire and a torsion spring. A bobbin is installed on the output shaft of the flipping motor. One end of the pull wire is connected to the bobbin. The flipping motor is fixed to a cover plate. The other end of the pull wire is fixed to another cover plate. The torsion spring is installed at the folding part of the bracket. When the line is reeled in, the torsion spring is compressed and the cover plate is folded, thereby realizing the folding of the entire wing; when the line is released, under the action of the restoring force of the torsion spring, the cover plate is laid flat, and the flexible folding area is also laid flat.

9. The foldable flapping-wing aircraft according to claim 1, characterized in that: The flexible folding area is 3D printed with TPU material, and the fuselage is a carbon rod; The flexible folding area is fan-shaped, semicircular, or scissor-worm wing-shaped.

10. The foldable flapping-wing aircraft according to claim 1, characterized in that: It also includes a servo steering engine, a controller, a power supply, and a receiver, which are all fixed to the fuselage through 3D printed connectors, the heater is directly fixed to the fuselage, and the rocker arm of the servo steering engine is connected to the bracket of the wing; The fuselage is connected to the brackets of the wing through carbon tubes.

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