Membrane wing aircraft, artificial muscle fiber steering engine structure based on antagonism structure and flight control method of membrane wing aircraft

Abstract

The invention discloses a membrane-wing aircraft, an artificial muscle fiber steering engine structure based on an antagonism structure and a flight control method of the membrane-wing aircraft. The steering engine structure comprises a longitudinal swing arm, a transverse support arm, a first artificial muscle fiber and a second artificial muscle fiber; the longitudinal swing arm is provided with a hinged end and a swing end, and the transverse support arm extends in the wingspan direction of the membrane wing aircraft. The hinged end is hinged to the main structure, the swing end is connected with the middle portion of the transverse supporting arm, the two ends of the first artificial muscle fiber are connected with the first end and the main structure respectively, the two ends of the second artificial muscle fiber are connected with the second end and the main structure respectively, and control points of the first wing membrane and the second wing membrane are fixedly connected with the transverse supporting arm. The steering engine structure provided by the invention adopts an antagonistic mechanical structure and can replace a steering engine and a transmission structure of a tail wing of a commercial membrane-wing aircraft, so that the flight direction is regulated and controlled; the artificial muscle fiber steering engine has lighter weight, lower energy consumption and considerable control flexibility, the weight of the ornithopter can be obviously reduced, and the flight efficiency of the ornithopter can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a membrane wing aircraft, an artificial muscle fiber servo structure based on an antagonistic structure thereof, and a flight control method. Background Art

[0002] Traditional membrane-wing aircraft typically rely on the synergy of servos and mechanical structures to achieve motion. However, the complexity and weight of rigid metal mechanical structures and servos have limited the development of some membrane-wing aircraft towards lightweight, flexible, and intelligent features. In recent years, the rapid development of linearly contracting artificial muscle fibers, as lightweight and flexible actuating elements, has the potential to replace servos and complex mechanical structures in some intelligent structures and systems, making operational equipment more intelligent and efficient.

[0003] At present, most reports on the application of linear contractile artificial muscle fibers rely on the contractile properties of the fibers themselves. A reasonable structure is a prerequisite for enriching the application of artificial muscle fibers. Even the commonly used metal servos require structural assistance to achieve optimal performance. There are still challenges in the adaptation of artificial muscle fibers to different service devices, which seriously limits the application and development of artificial muscle fibers. The contraction stroke of artificial muscle fibers can be amplified by a lever-saving structure. This simple structure has little impact on the expansion of the application scenarios of artificial muscle fibers. The application scenarios are mainly concentrated in model arms driven by artificial muscle fibers, deployable structures, simple grippers, etc. The reasonable adaptation between artificial muscle fibers and sophisticated structures can enrich their application scenarios and promote the rapid development of intelligent robots, but it cannot yet meet the application needs of membrane-wing aircraft.

[0004] Flapping-wing aircraft is a type of membrane-wing aircraft. As a bird-like aircraft, it has the advantages of strong maneuverability, high concealment, and low energy consumption. However, flight time is one of the key problems that restrict its further development. The flight time can be increased by adding battery packs, but the increase in its own weight will limit the flight efficiency, and the weight reduction of its structure is particularly important. In addition, the development of new structures, such as transmission structures and actuation structures, can promote the further development of flapping-wing aircraft. Another type of membrane-wing aircraft is the membrane-wing glider aircraft, which also faces similar technical problems and needs to find a balance between control flexibility, energy consumption and lightweight.

[0005] Artificial muscles are an important breakthrough in achieving the optimal balance between control flexibility, energy consumption and lightweight, but there is still a gap in the current existing technology in using artificial muscles to realize servo control. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a membrane wing aircraft, an artificial muscle fiber servo structure based on an antagonistic structure, and a flight control method thereof.

[0007] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0008] In a first aspect, the present invention provides a servo structure for a membrane wing aircraft, the membrane wing aircraft comprising a main structure and first and second wing membranes located on both sides of the main structure, the servo structure comprising a longitudinal swing arm, a transverse support arm, a first artificial muscle fiber, and a second artificial muscle fiber;

[0009] The longitudinal swing arm extends axially along the main structure and has a hinged end and a swinging end. The transverse support arm extends along the wingspan direction of the membrane wing aircraft and includes a first end, a middle part and a second end arranged in sequence along the wingspan direction; the hinged end is hinged to the main structure, and the swinging end is connected to the middle part. The two ends of the first artificial muscle fiber are respectively connected to the first end and the main structure, and the two ends of the second artificial muscle are respectively connected to the second end and the main structure. The control points of the first wing membrane and the second wing membrane are fixedly connected to the transverse support arm, and the control points are used to adjust the effective area of ​​the first wing membrane or the second wing membrane by their own movement along the wingspan direction.

[0010] In a second aspect, the present invention further provides a membrane wing aircraft having the above-mentioned servo structure.

[0011] In a third aspect, the present invention further provides a flight control method for the membrane wing aircraft, comprising:

[0012] Different current intensities are applied to the first artificial muscle fiber and the second artificial muscle fiber, so that the control point moves in an offset direction along the wingspan.

[0013] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least:

[0014] The servo structure provided by the present invention is an artificial muscle fiber servo with an antagonistic mechanical structure, which can replace the servo and transmission structure of the tail wing of a commercial membrane wing aircraft to achieve flight direction control; compared with the metal servo and transmission structure of a commercial flapping wing aircraft, the artificial muscle fiber servo has a lighter weight and lower energy consumption, while also having considerable control flexibility, which can significantly reduce the weight of the flapping wing aircraft and improve its flight efficiency.

[0015] The above description is only an overview of the technical solution of the present invention. In order to enable those skilled in the art to more clearly understand the technical means of this application and implement them according to the contents of the specification, the following is an explanation of the preferred embodiments of the present invention with detailed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a directional control application of a steering gear structure provided by a typical embodiment of the present invention;

[0017] Figure 2 This is a physical photo of a steering gear structure provided by a typical embodiment of the present invention;

[0018] Figure 3 This is a control circuit diagram of a servo structure provided by a typical embodiment of the present invention;

[0019] Figure 4 This is a weight comparison diagram of a steering gear structure provided by a typical embodiment of the present invention and a commercial steering gear structure;

[0020] Figure 5 This is an example diagram of the working mechanism of the steering gear structure provided by a typical embodiment of the present invention;

[0021] Figure 6 This is a test diagram of the flight direction control performance of a flapping-wing aircraft provided by a typical implementation case of the present invention. DETAILED DESCRIPTION

[0022] As mentioned above, the existing technology mainly has the following shortcomings:

[0023] ) Traditional servos are heavy and consume high power;

[0024] The actuator device made of pneumatic artificial muscle fibers is complex and not suitable for flying robots;

[0025] ) Nickel-titanium alloy wire drivers have high power consumption, slow heat dissipation, and metal fatigue.

[0026] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The following will further explain this technical solution, its implementation process and principles.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0028] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component or method step from another with the same name, but do not necessarily require or imply any actual relationship or order between these components or method steps.

[0029] The purpose of the present invention is to design a lightweight, low-energy artificial muscle fiber servo to realize the flight direction control application of membrane wing aircraft.

[0030] Based on the above-mentioned purpose, with reference to the figures and as shown in the figures, an embodiment of the present invention provides a servo structure of a membrane wing aircraft, the membrane wing aircraft having a main structure and a first wing membrane and a second wing membrane located on both sides of the main structure, characterized in that the servo structure includes a longitudinal swing arm, a transverse support arm, a first artificial muscle fiber, and a second artificial muscle fiber; the longitudinal swing arm extends axially along the main structure and has a hinged end and a swinging end, the transverse support arm extends along the wingspan direction of the membrane wing aircraft and includes a first end, a middle part and a second end arranged in sequence along the wingspan direction; the hinged end is hinged to the main structure, and the swinging end is connected to the middle part, the two ends of the first artificial muscle fiber are respectively connected to the first end and the main structure, the two ends of the second artificial muscle are respectively connected to the second end and the main structure, the control points of the first wing membrane and the second wing membrane are fixedly connected to the transverse support arm, and the control points are used to adjust the effective area of ​​the first wing membrane or the second wing membrane by their own movement along the wingspan direction.

[0031] In some embodiments, the membrane-wing aircraft comprises any one of a flapping-wing aircraft and a gliding aircraft.

[0032] In some embodiments, the hinged end is further away from the tail of the main structure than the swinging end.

[0033] In some embodiments, the first artificial muscle and the second artificial muscle have an antagonistic relationship, and in the process of driving the control point to move along the wingspan direction, the first artificial muscle and the second artificial muscle are both in an extended state.

[0034] As some typical application examples of the present invention, the preparation process of the servo structure applied to flapping-wing aircraft can be as follows:

[0035] Steps: Use a thin carbon fiber plate as a transverse support arm, and its center is horizontally fixed on one end of a carbon fiber rod (i.e., the swing end). The carbon fiber rod serves as a longitudinal swing arm, and the other end (i.e., the hinged end) is fixed on the main structure of the membrane wing aircraft without restricting the hinged rotation. The two are installed as a whole at the tail of the flapping wing aircraft (of course, it is not limited to being installed at other positions such as the head of the aircraft).

[0036] Steps: On both sides of the carbon fiber plate, about centimeters away from the center, anchor points for connecting the first wing membrane or the second wing membrane on both sides of the flapping-wing aircraft are fixed respectively, and the tail ends of the first wing membrane or the second wing membrane on both sides (i.e., the control points) are hung on these two anchor points. Of course, in the present invention, as long as the control points can be achieved relative to the main structure along the wingspan direction.

[0037] Steps: One end of each artificial muscle fiber is connected to the end of the transverse arm, while the other end is fixed to the main fuselage structure of the flapping-wing aircraft.

[0038] In some embodiments, the servo structure also includes a control circuit, which includes a DC power supply, a reversing switch, a first diode and a second diode. The first artificial muscle and the first diode are connected in series to form a first control unit, and the second artificial muscle and the second diode are connected in series to form a second control unit. The first control unit and the second control unit are connected in parallel and the conduction directions of the first diode and the second diode are opposite; the input end of the reversing switch is connected to the DC power supply, and the output end is connected to the two ends of the first control unit and the second control unit respectively, and can switch the direction of the voltage applied to the two ends of the first control unit and the second control unit.

[0039] In some embodiments, the reversing switch includes a first switching switch and a second switching switch, the first switching switch has a first input terminal, a first output terminal, and a second output terminal, and the second switching switch has a second input terminal, a third output terminal, and a fourth output terminal; the positive pole of the DC power supply is connected to the first input terminal, and the negative pole is connected to the second input terminal; the first output terminal, the fourth output terminal and one end of the parallel connection of the first control unit and the second control unit are conductive, and the second output terminal, the third output terminal and the other end of the parallel connection of the first control unit and the second control unit are conductive.

[0040] See the figure for a schematic diagram of an artificial muscle fiber servo replacing the original flight control servo on a commercial flapping-wing aircraft's tail. A simple control circuit was designed for the artificial muscle fiber servo. Unidirectional Schottky diodes enable selective current control of the left and right artificial muscle fibers in an antagonistic configuration. Two artificial muscle fibers are each connected in series with a diode, and then connected in parallel to form a whole. The diodes steer in opposite directions. The power supply to the artificial muscle fibers is controlled by the left and right deflection switches of a Bluetooth remote control.

[0041] In some embodiments, the material of the longitudinal swing arm and the transverse support arm includes any one or a combination of two or more of carbon fiber, aramid, glass fiber, metal matrix composite material, aluminum alloy, and magnesium alloy.

[0042] In some embodiments, the material of the first artificial muscle fiber and the second artificial muscle fiber includes any one or a combination of two or more of nylon silicone elastomer core-sheath composite fibers, carbon nanotube fibers and their composite fibers, polydimethylsiloxane fibers and their composite fibers, nylon fibers and their composite fibers, aramid fibers and their composite fibers, polyimide fibers and their composite fibers, liquid crystal elastomer fibers and their composite fibers, and carbon fibers and their composite fibers.

[0043] As a typical example, the carbon fiber rods and carbon fiber plates in the steps described above can be replaced by other lightweight, high-strength composite materials (such as aramid, glass fiber, metal-based composite materials, aluminum alloy, magnesium alloy, lightweight, high-strength metals, etc.); the anchor point is fixed about centimeters away from the center in the steps, and the distance can be changed according to actual needs, which can be centimeters, centimeters, centimeters or larger; the nylon@silicone elastomer artificial muscle fibers used in the steps can be replaced by artificial muscle fibers prepared from other materials or composite materials, such as carbon nanotube fibers and their composite fibers, polydimethylsiloxane fibers and their composite fibers, nylon fibers and their composite fibers, aramid fibers and their composite fibers, polyimide fibers and their composite fibers, liquid crystal elastomer fibers and their composite fibers, carbon fiber composite fibers, etc.

[0044] An embodiment of the present invention further provides a membrane wing aircraft, which has the servo structure provided by any one of the above embodiments.

[0045] An embodiment of the present invention further provides a flight control method for a membrane wing aircraft, which includes the following steps:

[0046] Different current intensities are applied to the first artificial muscle fiber and the second artificial muscle fiber, so that the control point moves in an offset direction along the wingspan.

[0047] The above-mentioned different current intensities can be different current sizes, for example, the current on one side is larger and the current on the other side is smaller, so the larger current will be relatively contracted, and the smaller current will be stretched; it can also be that current is applied on one side and the current on the other side is; in addition, when the servo does not need to turn and maintain straight flight, the current intensity on both sides can be made equal, so that the tension on both sides is balanced to keep the rudder centered.

[0048] The figure compares the weight of two artificial muscle fibers with that of a commercial servo. The artificial muscle fiber servo weighs approximately 100 grams, which is only 100% of the weight of a commercial servo and transmission structure. This shows that artificial muscle fiber servos have a significant weight reduction effect compared to traditional commercial servos.

[0049] The figure illustrates the working mechanism of the artificial muscle fiber servo. Constrained by a central control carbon fiber rod, the left and right swing of a carbon fiber plate changes the effective surface area of ​​the flapping-wing aircraft's wing membranes, thereby changing the aircraft's flight direction. The plate's movement is achieved by artificial muscle fibers attached to either side of the rod's center point. This design creates an antagonistic structure with the artificial muscle fibers on either side. When the artificial muscle fibers on the right side of the flapping-wing aircraft contract, they stretch the muscle fibers on the other side, causing the plate to tilt to the left. This loss of tension on the left wing membrane reduces the effective surface area of ​​the left wing, causing the aircraft to turn to the left. After power is removed, the contracted artificial muscle fibers return to their original length, allowing the aircraft to fly straight and steady. Furthermore, to accelerate the recovery of contracted artificial muscle fibers, electrical heat can be used to drive the stretched artificial muscle fibers on the other side to contract, quickly returning the structure to its original state. To turn right, the artificial muscle fibers on the other side contract, following the same operating principle discussed above.

[0050] The figure shows a test of the flight direction control performance of an artificial muscle fiber servo during actual flight of a flapping-wing aircraft. By using the artificial muscle fiber servo at the tail of the flapping-wing aircraft, the flapping-wing aircraft can change its flight direction smoothly and quickly. When the artificial muscle fibers are not working, the antagonistic structure remains stable, allowing the bird aircraft to fly straight and without deviation (i). When the right artificial muscle fibers are contracted, the flapping-wing aircraft turns left (II); when the left muscle fibers are activated, the flapping-wing aircraft turns right (III). More importantly, the flapping-wing aircraft can achieve continuous directional control from left to right IV. During this process, after the right artificial muscle fibers complete contraction, the left artificial muscle fibers are immediately stimulated by electricity and contract.

[0051] According to the above embodiments, the key technical contributions of the present invention are as follows: proposing the design concept of artificial muscle fiber servo;

[0052] : The application of artificial muscle fiber servo for flapping-wing aircraft flight direction control is realized; : The control circuit design of artificial muscle fiber servo; : The design idea of ​​antagonistic structure for artificial muscle fiber servo; : Provides an antagonistic structure servo driven by artificial muscle fiber that has been verified to have significant improvement effects.

[0053] The design concept of the servo structure provided by the present invention has the following advantages: the artificial muscle fiber servo is light in weight, simple in structure and efficient; the artificial muscle fiber servo based on the antagonistic structure is highly universal and can be applied to other intelligent devices; the artificial muscle fiber actuating unit has low power consumption and high energy density; the artificial muscle fiber servo technology is novel and highly innovative.

[0054] It should be understood that the above embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent variations or modifications made in accordance with the spirit and substance of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A servo structure for a membrane wing aircraft, the membrane wing aircraft comprising a main structure and a first wing membrane and a second wing membrane located on both sides of the main structure, characterized in that: The steering gear structure includes a longitudinal swing arm, a transverse support arm, a first artificial muscle fiber, and a second artificial muscle fiber; The longitudinal swing arm extends axially along the main structure and has a hinged end and a swinging end. The transverse support arm extends along the wingspan direction of the membrane wing aircraft and includes a first end, a middle part and a second end arranged in sequence along the wingspan direction; the hinged end is hinged to the main structure, and the swinging end is connected to the middle part. The two ends of the first artificial muscle fiber are respectively connected to the first end and the main structure, and the two ends of the second artificial muscle are respectively connected to the second end and the main structure. The control points of the first wing membrane and the second wing membrane are fixedly connected to the transverse support arm, and the control points are used to adjust the effective area of ​​the first wing membrane or the second wing membrane by their own movement along the wingspan direction.

2. The steering gear structure according to claim 1, characterized in that: The membrane wing aircraft includes any one of a flapping wing aircraft and a gliding aircraft.

3. The steering gear structure according to claim 1, characterized in that: The hinged end is further away from the tail of the main structure than the swinging end.

4. The steering gear structure according to claim 1, characterized in that: The first artificial muscle and the second artificial muscle have an antagonistic relationship. When driving the control point to move along the wingspan direction, the first artificial muscle and the second artificial muscle are both in an extended state.

5. The steering gear structure according to claim 4, characterized in that: The invention also includes a control circuit, the control circuit including a DC power supply, a reversing switch, a first diode and a second diode, the first artificial muscle and the first diode are connected in series to form a first control unit, the second artificial muscle and the second diode are connected in series to form a second control unit, the first control unit and the second control unit are connected in parallel, and the first diode and the second diode are conductive in opposite directions; The input end of the reversing switch is electrically connected to the DC power supply, and the output end is respectively connected to the two ends of the first control unit and the second control unit, and can switch the direction of the voltage applied to the two ends of the first control unit and the second control unit.

6. The steering gear structure according to claim 5, characterized in that: The reversing switch includes a first switching switch and a second switching switch, wherein the first switching switch has a first input terminal, a first output terminal, and a second output terminal, and the second switching switch has a second input terminal, a third output terminal, and a fourth output terminal; The positive pole of the DC power supply is connected to the first input end, and the negative pole is connected to the second input end; the first output end, the fourth output end and one end of the first control unit and the second control unit in parallel are conductively connected, and the second output end, the third output end and the other end of the first control unit and the second control unit in parallel are conductively connected.

7. The steering gear structure according to claim 1, characterized in that: The material of the longitudinal swing arm and the transverse support arm includes any one or a combination of two or more of carbon fiber, aramid, glass fiber, metal matrix composite material, aluminum alloy, and magnesium alloy.

8. The steering gear structure according to claim 1, characterized in that: The materials of the first artificial muscle fiber and the second artificial muscle fiber include any one or a combination of two or more of nylon-silicone elastomer core-sheath composite fibers, carbon nanotube fibers and their composite fibers, polydimethylsiloxane fibers and their composite fibers, nylon fibers and their composite fibers, aramid fibers and their composite fibers, polyimide fibers and their composite fibers, liquid crystal elastomer fibers and their composite fibers, and carbon fibers and their composite fibers.

9. A membrane wing aircraft, characterized in that: The membrane wing aircraft has the servo structure described in any one of claims 1-8.

10. The flight control method of a membrane wing aircraft according to claim 9, characterized in that: include: Different current intensities are applied to the first artificial muscle fiber and the second artificial muscle fiber, so that the control point moves in an offset direction along the wingspan.

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