Single-degree-of-freedom variant unmanned aerial vehicle driving mechanism capable of achieving synchronous structure changing

Abstract

The invention discloses a single-degree-of-freedom variant unmanned aerial vehicle driving mechanism capable of realizing synchronous structure change, and relates to the technical fields of machinery, mechanics, unmanned aerial vehicles and the like. The problem that the folding type variant unmanned aerial vehicle rolls due to inconsistent folding processes of wings on the two sides is solved. The mechanism is used for driving the morphing unmanned aerial vehicle to be switched between a folding state and an unfolding state, folding and unfolding of the folding type morphing unmanned aerial vehicle are achieved only through the mode that one power source is matched with the lead screw, the complexity of the mechanism is simplified, meanwhile, it is guaranteed that the folding process is highly symmetrical, and it is guaranteed that the folding angles on the two sides are the same; the problem that the folding type variant unmanned aerial vehicle rolls due to inconsistent folding processes of wings on the two sides is solved, and therefore the folding type variant unmanned aerial vehicle has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical fields of machinery, mechanics, unmanned aerial vehicles, etc., and specifically refers to a single-degree-of-freedom variable unmanned aerial vehicle drive mechanism capable of realizing synchronous variable structure. Background Art

[0002] Since the Wright brothers manufactured the first unmanned aerial vehicle, various countries have now designed unmanned aerial vehicles to meet various mission requirements. However, current fixed-wing unmanned aerial vehicles cannot meet the increasingly complex flight environment and multi-mission requirements. Traditional aircraft are usually designed for a specific flight state and can exhibit good performance in that flight state, but their performance will decline in other flight states. With the continuous accumulation of aircraft design research experience and the progress of other disciplinary technologies, to overcome the shortcomings of this single-task mode of traditional aircraft, scientists have proposed the concept of variable aircraft.

[0003] A variable aircraft comprehensively applies new intelligent materials, variable drive mechanisms, and sensors to the aircraft, and improves its aerodynamic characteristics by compliant, smooth, and autonomous changes in the local or overall shape of the aircraft, so as to adapt to different flight conditions with excellent performance and complete various flight tasks more efficiently. It is a new concept aircraft with flight adaptability. During flight, a variable aircraft can effectively improve its flight performance, expand the flight envelope, and increase flight efficiency by changing its shape.

[0004] The foldable variable unmanned aerial vehicle can perform cruise reconnaissance when its wings are deployed, and can perform high-speed strikes after the wings are folded. Compared with the traditional fixed-shape design, it can meet multi-mission requirements and has wide applicability. The foldable variable unmanned aerial vehicle is an inevitable choice for future aircraft to meet multi-mission requirements. Conducting research on related technologies of foldable variable aircraft can provide important support for the development of space resources and the maintenance of national security.

[0005] A major difficulty in the design process of a foldable variable unmanned aerial vehicle is the design of an ultra-low-dimensional variable drive mechanism under strong symmetry constraints. Currently, NASA's 8-motor drive scheme uses eight motors to drive eight hinges, which cannot ensure that the folding process of the variable unmanned aerial vehicle is highly consistent. When the folding angles on both sides are different, the unmanned aerial vehicle will roll, causing serious flight accidents. The present invention combines a motor and a lead screw, and only one motor can complete the deployment and folding of the wings, solving the design of the variable drive mechanism with ultra-low dimensions and strong constraint characteristics, and meeting the deformation symmetry. Summary of the Invention

[0006] In view of the above problems, the present invention proposes a driving mechanism for a single-degree-of-freedom variable-form unmanned aerial vehicle (UAV) that can achieve synchronous deformation. By means of the cooperation between a motor and a lead screw, the folding and unfolding of a folding variable-form UAV are realized with only one power source, simplifying the complexity of the mechanism, achieving the unfolding and folding of both wings, ensuring high synchronization during the folding process, ensuring that the folding angles on both sides are the same, and solving the problem of rollover of the folding variable-form UAV due to inconsistent folding processes of the two wings.

[0007] The technical solution of the present invention is as follows: It is used to drive a variable-form UAV to switch between a folded state and an unfolded state. The variable-form UAV includes a fuselage, a pair of inner wings, a pair of outer wings, and a framework.

[0008] The framework includes a carbon plate 6, a carbon tube 7, and a fixture 5. The carbon tube 7 is divided into an inner carbon tube 71 and an outer carbon tube 72. The fixture 5 is divided into an inner fixture 51 and an outer fixture 52.

[0009] The fuselage is fixedly installed on a pair of parallel carbon plates 6. Two inner fixtures 51 are rotatably connected to both ends of each carbon plate 6. The inner carbon tube 71 is fixedly installed on the inner fixture 51. The end of the inner carbon tube 71 away from the fuselage is rotatably connected to the outer fixture 52. The outer carbon tube 72 is fixedly installed on the outer fixture 52. The carbon plate 6, the inner carbon tube 71, and the outer carbon tube 72 are all arranged along the width direction of the variable-form UAV. The inner wing is fixedly installed on the inner carbon tube 71, and the outer wing is detachably installed on the outer carbon tube 72.

[0010] The driving mechanism includes a single-degree-of-freedom driving unit 1, a pair of main beams 2, a pair of outer beams 3, and two pairs of transmission shafts 4. Both the head and the tail ends of the single-degree-of-freedom driving unit 1 are fixedly installed at the central positions of the two carbon plates 6 and are arranged along the length direction of the UAV fuselage. The pair of main beams 2 are fixedly connected to each other through a main beam connecting member, and this main beam connecting member is connected to the output of the single-degree-of-freedom driving unit 1. The single-degree-of-freedom driving unit 1 drives the pair of main beams 2 to perform synchronous reciprocating motion back and forth.

[0011] The transmission shaft 4 is divided into an inner transmission shaft 41 and an outer transmission shaft 42. Both ends of the inner transmission shaft 41 are fixedly connected to the inner fixture 51, and both ends of the outer transmission shaft 42 are fixedly connected to the outer fixture 52, so that the inner transmission shaft 41 rotates synchronously with the inner carbon tube 71, and the outer transmission shaft 42 rotates synchronously with the outer carbon tube 72. The end of the main beam 2 away from the main beam connecting member is sleeved on the inner transmission shaft 41, and both ends of the outer beam 3 are respectively sleeved on the inner transmission shaft 41 and the outer transmission shaft 42. After the single-degree-of-freedom driving unit 1 is started, the inner transmission shaft 41 and the outer transmission shaft 42 rotate synchronously in opposite directions.

[0012] Further, the single-degree-of-freedom driving unit 1 includes a lead screw, a nut, a motor, and a lead screw mounting seat. The head and tail ends of the lead screw mounting seat are fixedly installed at the central positions of the two carbon plates 6. The housing of the motor is fixedly installed on the lead screw mounting seat, and the output shaft of the motor is fixedly connected to one end of the lead screw. The other end of the lead screw is rotatably connected to the lead screw mounting seat. The nut is sleeved on the lead screw and is threadedly connected thereto. The main beam connecting member is fixedly connected to the nut.

[0013] Further, at least one first helical groove is formed on the surface of the inner transmission shaft 71. A first slider is slidably accommodated in the first helical groove. The first slider is fixedly installed in the inner sleeve 81 sleeved on the inner transmission shaft 71. The end of the main beam 2 is sleeved on the inner sleeve 81 and is fixedly connected to the inner sleeve 81. The end of the outer beam 3 is directly sleeved on the inner transmission shaft 71 and abuts against both end faces of the inner sleeve 81, and performs an axial reciprocating motion synchronized with the inner sleeve 81. Thus, during the linear motion of the main beam 2, the inner transmission shaft 71 is driven to rotate, and the outer beam 3 is driven to perform a synchronous linear motion.

[0014] Further, at least one second helical groove is formed on the surface of the outer transmission shaft 72. The second helical groove has a helical direction opposite to that of the first helical groove. A second slider is slidably accommodated in the second helical groove. The second slider is fixedly installed in the outer sleeve 82 sleeved on the outer transmission shaft 72. The end of the outer beam 3 is sleeved on the outer sleeve 82 and is fixedly connected to the outer sleeve 82. Thus, during the linear motion of the outer beam 3, the outer transmission shaft 72 is driven to rotate, realizing synchronous reverse rotation of the inner transmission shaft 41 and the outer transmission shaft 42. Finally, during the upward folding process of the inner wing, the outer wing can be driven to move upward in a translational manner.

[0015] Further, the outer carbon tube 72 penetrates through the outer wing, and there is a clearance fit at the penetration position. At the end position of the outer carbon tube 72, a mounting plate is fixedly installed that fits against the inner end face of the inner wing. A clamping shaft 91 penetrating through the mounting plate is fixedly installed on the inner end face of the inner wing. A plug plate 92 perpendicular to the clamping shaft 91 is slidably connected to the surface of the mounting plate. An annular slot is provided on the surface of the clamping shaft 91, and a plugging opening adapted to the annular slot is formed on the plug plate 92.

[0016] The present invention has the following beneficial effects:

[0017] 1. By combining a single-degree-of-freedom drive unit, beam elements, and a drive shaft, a variant drive mechanism design under ultra-low-dimensional strong constraints is achieved. The folding and unfolding of a folding variant unmanned aerial vehicle are realized only by the cooperation of a single power source and a lead screw, which simplifies the complexity of the mechanism, realizes the unfolding and folding of both wings, ensures a high degree of synchronization during the folding process, and guarantees the same folding angle on both sides, solving the problem of roll caused by inconsistent folding processes of the two wings of the folding variant unmanned aerial vehicle.

[0018] 2. On the premise of comprehensively considering the structural load-bearing capacity, both the main structural beam and the outer beam adopt a hollow design to maximize the reduction of the structural self-weight.

[0019] 3. In this case, it is particularly considered that the outer wing needs to bear aerodynamic loads. When the outer wing bears aerodynamic loads and superimposes the torque during variant deformation, the outer wing body and the connection positions are prone to damage. Therefore, in this case, the connection structure of the outer wing is optimized, and the fixed connection is improved to a snap connection after nesting carbon tubes, which plays a role in protecting the outer wing.

[0020] 4. Compared with the existing variant drive mechanisms, the single-degree-of-freedom variant unmanned aerial vehicle drive mechanism capable of synchronous structure change proposed by the present invention firstly has an advanced principle and can complete the folding and unfolding tasks of the unmanned aerial vehicle; secondly, this structure is convenient for processing, and batch manufacturing can be realized with existing processing technologies and assembly; finally, through the single-degree-of-freedom attribute of the hinge structure, while ensuring the structural strength, it can better maintain the symmetry of the mechanism folding, which is crucial for the safety and stability of folding variant flight.

[0021] The present invention realizes the folding and unfolding of a folding variant unmanned aerial vehicle only by the cooperation of a single power source and a lead screw, simplifies the complexity of the mechanism, and at the same time ensures a high degree of symmetry during the folding process, guarantees the same folding angle on both sides, and solves the problem of roll caused by inconsistent folding processes of the two wings of the folding variant unmanned aerial vehicle. Therefore, the present invention has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present case in the unfolded state,

[0023] Figure 2 is a schematic structural diagram of the present case in the folded state,

[0024] Figure 3 is a schematic structural diagram of the left main beam of the present case,

[0025] Figure 4 is a schematic structural diagram of the right main beam of the present case,

[0026] Figure 5 is a schematic structural diagram of the main beam connecting piece of the present case,

[0027] Figure 6 It is a schematic structural diagram of the left outer beam in this case.

[0028] Figure 7 It is a schematic structural diagram of the right outer beam in this case.

[0029] Figure 8 It is a schematic structural diagram of the inner transmission shaft.

[0030] Figure 9 It is a schematic diagram of the detachable mounting structure of the outer wing.

[0031] Figure 10 It is a schematic diagram of the implementation manner in this case.

[0032] In the figure, 1 is a single-degree-of-freedom drive unit, 2 is the main beam, 3 is the outer beam, 4 is the transmission shaft, 41 is the inner transmission shaft, 42 is the outer transmission shaft, 5 is the fixator; 51 is the inner fixator, 52 is the outer fixator; 6 is the carbon plate, 7 is the carbon tube, 71 is the inner carbon tube, 72 is the outer carbon tube; 81 is the inner sleeve, 82 is the outer sleeve, 91 is the clamping shaft, 92 is the insertion plate. Detailed implementation manner

[0033] To clearly illustrate the technical features of this patent, the following will elaborate on this patent in detail through specific implementation manners and in combination with its accompanying drawings.

[0034] As Figure 1 、 2 shown, the single-degree-of-freedom variant UAV drive mechanism capable of realizing synchronous variable structure can be conveniently switched between the unfolded state and the folded state, thereby completing the folding and unfolding processes of the folding variant UAV to adapt to various different flight scenarios. To achieve the switching between the unfolded state and the folded state, its structure is specifically as follows:

[0035] The single-degree-of-freedom variant UAV drive mechanism capable of realizing synchronous variable structure is used to drive the variant UAV to switch between the folded state and the unfolded state. The variant UAV includes a fuselage, a pair of inner wings, a pair of outer wings, and a framework.

[0036] The framework includes a carbon plate 6, a carbon tube 7, and a fixator 5. The carbon tube 7 is divided into an inner carbon tube 71 and an outer carbon tube 72, and the fixator 5 is divided into an inner fixator 51 and an outer fixator 52.

[0037] The fuselage is fixedly installed on a pair of parallel carbon plates 6. Two inner fixators 51 are rotatably connected to both ends of each carbon plate 6. An inner carbon tube 71 is fixedly installed on the inner fixator 51. One end of the inner carbon tube 71 away from the fuselage is rotatably connected to an outer fixator 52. An outer carbon tube 72 is fixedly installed on the outer fixator 52; the carbon plates 6, the inner carbon tubes 71, and the outer carbon tubes 72 are all arranged along the width direction of the variable unmanned aerial vehicle; the inner wing is fixedly installed on the inner carbon tube 71, and the outer wing is detachably installed on the outer carbon tube 72;

[0038] The driving mechanism includes a single-degree-of-freedom driving unit 1, a pair of main beams 2, a pair of outer beams 3, and two pairs of transmission shafts 4. Both the head and the tail of the single-degree-of-freedom driving unit 1 are fixedly installed at the central positions of the two carbon plates 6 and are arranged along the length direction of the unmanned aerial vehicle fuselage. The two main beams 2 are fixedly connected to each other through a main beam connecting piece, and this main beam connecting piece is connected to the output of the single-degree-of-freedom driving unit 1. The single-degree-of-freedom driving unit 1 drives the pair of main beams 2 to move back and forth synchronously in the front and rear directions;

[0039] The transmission shaft 4 is divided into an inner transmission shaft 41 and an outer transmission shaft 42. Both ends of the inner transmission shaft 41 are fixedly connected to the inner fixator 51, and both ends of the outer transmission shaft 42 are fixedly connected to the outer fixator 52, so that the inner transmission shaft 41 rotates synchronously with the inner carbon tube 71, and the outer transmission shaft 42 rotates synchronously with the outer carbon tube 72; One end of the main beam 2 away from the main beam connecting piece is sleeved on the inner transmission shaft 41, and both ends of the outer beam 3 are respectively sleeved on the inner transmission shaft 41 and the outer transmission shaft 42. After the single-degree-of-freedom driving unit 1 is started, the inner transmission shaft 41 and the outer transmission shaft 42 rotate synchronously in the opposite directions.

[0040] The single-degree-of-freedom driving unit 1 includes a lead screw, a nut, a motor, and a lead screw mounting seat. Both the head and the tail of the lead screw mounting seat are fixedly installed at the central positions of the two carbon plates 6. The housing of the motor is fixedly installed on the lead screw mounting seat, and the output shaft of the motor is fixedly connected to one end of the lead screw. The other end of the lead screw is rotatably connected to the lead screw mounting seat. The nut is sleeved on the lead screw and is threadedly connected to it. The main beam connecting piece is fixedly connected to the nut.

[0041] At least one first helical groove is formed on the surface of the inner transmission shaft 71. A first slider is slidably accommodated in the first helical groove. The first slider is fixedly installed in an inner sleeve 81 sleeved on the inner transmission shaft 71. The end of the main beam 2 is sleeved on the inner sleeve 81 and is fixedly connected to the inner sleeve 81. The end of the outer beam 3 is directly sleeved on the inner transmission shaft 71 and abuts against both end faces of the inner sleeve 81, and moves back and forth axially synchronously with the inner sleeve 81; thus, during the linear movement of the main beam 2, the inner transmission shaft 71 is driven to rotate, and the outer beam 3 is driven to move linearly synchronously;

[0042] At least one second helical groove is formed on the surface of the outer transmission shaft 72. The second helical groove has a helical direction opposite to that of the first helical groove. A second slider is slidably received in the second helical groove. The second slider is fixedly installed in an outer sleeve 82 sleeved on the outer transmission shaft 72. The end of the outer beam 3 is sleeved on the outer sleeve 82 and is fixedly connected to the outer sleeve 82. Thus, during the linear movement of the outer beam 3, the outer transmission shaft 72 is driven to rotate, so as to realize the synchronous reverse rotation of the inner transmission shaft 41 and the outer transmission shaft 42. Finally, during the upward folding process of the inner wing, the outer wing can be translated upward.

[0043] The helical directions of the grooves of the inner and outer drive shafts are opposite, so that the flipping directions of the inner folding wing and the outer folding wing are opposite, and thus the convenient switching between the unfolded state and the folded state as shown in Figure 1 、 2 can be realized. Through the movement of the single-degree-of-freedom drive unit and in cooperation with the single-degree-of-freedom deformation hinge, the inner folding wings can move symmetrically towards each other, and the movement range is from 0 degree to 120 degrees. During this process, it can be ensured that the outer wings on both sides remain horizontal.

[0044] Regarding the detachable installation of the outer wing:

[0045] The outer carbon tube 72 penetrates through the outer wing, and there is a clearance fit between the penetration positions of the two. At the end position of the outer carbon tube 72, a mounting plate is fixedly installed which fits against the inner end face of the inner wing. A clamping shaft 91 penetrating through the mounting plate is fixedly installed on the inner end face of the inner wing. A plug plate 92 perpendicular to the clamping shaft 91 is slidably connected to the surface of the mounting plate. An annular slot is provided on the surface of the clamping shaft 91, and a plugging opening adapted to the annular slot is formed on the plug plate 92. In this way, through the cooperation of the plug plate after plugging and the clamping shaft, the position is locked in the width direction of the outer wing, but the clearance fit between the outer carbon tube 72 and the outer wing is retained. Thus, when the outer wing bears the aerodynamic load and is superimposed with the variant torque, a small elastic deformation space is provided for the outer wing by means of the clearance, so as to effectively protect the structural strength of the outer wing body and the connection stability of the connection position.

[0046] There are many specific implementation ways of the present invention. The above description is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements can be made, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A single-degree-of-freedom variant UAV driving mechanism capable of achieving synchronous conformational change, characterized in that: Used to drive the variant drone to switch between a folded state and an unfolded state, wherein the variant drone includes a fuselage, a pair of inner wings, a pair of outer wings and a frame; The skeleton comprises a carbon plate (6), a carbon tube (7) and a fixer (5), the carbon tube (7) is divided into an inner carbon tube (71) and an outer carbon tube (72), and the fixer (5) is divided into an inner fixer (51) and an outer fixer (52); The fuselage is fixedly mounted on a pair of parallel carbon plates (6), the two ends of each carbon plate (6) are rotatably connected to two internal fixers (51), an internal carbon tube (71) is fixedly mounted on the internal fixer (51), one end of the internal carbon tube (71) away from the fuselage is rotatably connected to an external fixer (52), and an external carbon tube (72) is fixedly mounted on the external fixer (52); the carbon plates (6), the internal carbon tube (71), and the external carbon tube (72) are all arranged along the width direction of the variant UAV; the inner wing is fixedly mounted on the inner carbon tube (71), and the outer wing is detachably mounted on the outer carbon tube (72); The driving mechanism comprises a single-degree-of-freedom driving unit (1), a pair of main beams (2), a pair of outer beams (3) and two pairs of transmission shafts (4); the head and tail ends of the single-degree-of-freedom driving unit (1) are fixedly mounted at the center of two carbon plates (6) and are arranged along the length direction of the drone fuselage; the pair of main beams (2) are fixedly connected via a main beam connecting piece, and the main beam connecting piece is connected to the output of the single-degree-of-freedom driving unit (1); the single-degree-of-freedom driving unit (1) drives the pair of main beams (2) to synchronously reciprocate forward and backward; The transmission shaft (4) is divided into an inner transmission shaft (41) and an outer transmission shaft (42); the two ends of the inner transmission shaft (41) are fixedly connected to the inner fixer (51), and the two ends of the outer transmission shaft (42) are fixedly connected to the outer fixer (52), so that the inner transmission shaft (41) rotates synchronously with the inner carbon tube (71), and the outer transmission shaft (42) rotates synchronously with the outer carbon tube (72); one end of the main beam (2) away from the main beam connecting member is sleeved on the inner transmission shaft (41), and the two ends of the outer beam (3) are respectively sleeved on the inner transmission shaft (41) and the outer transmission shaft (42); after the single-degree-of-freedom drive unit (1) is started, the inner transmission shaft (41) and the outer transmission shaft (42) rotate synchronously in opposite directions.

2. A single-degree-of-freedom variant UAV driving mechanism capable of achieving synchronous conformational change according to claim 1, characterized in that: The single-degree-of-freedom drive unit (1) comprises a lead screw, a nut, a motor and a lead screw mounting seat, wherein both ends of the lead screw mounting seat are fixedly mounted at the center of two carbon plates (6), the housing of the motor is fixedly mounted on the lead screw mounting seat, and the output shaft of the motor is fixedly connected to one end of the lead screw, the other end of the lead screw is rotatably connected to the lead screw mounting seat, the nut is sleeved on the lead screw and is threadedly connected to the lead screw, and the main beam connecting piece is fixedly connected to the nut.

3. The single-degree-of-freedom variant UAV driving mechanism capable of realizing synchronous conformational change according to claim 1, characterized in that: The surface of the inner transmission shaft (71) is provided with at least one first spiral groove, a first slider is slidably accommodated in the first spiral groove, and the first slider is fixedly mounted in an inner sleeve (81) sleeved on the inner transmission shaft (71). The end of the main beam (2) is sleeved on the inner sleeve (81) and is fixedly connected to the inner sleeve (81). The end of the outer beam (3) is directly sleeved on the inner transmission shaft (71) and abuts against the end surfaces of both sides of the inner sleeve (81), and maintains synchronous axial reciprocating motion with the inner sleeve (81); thereby, during the linear motion of the main beam (2), the inner transmission shaft (71) is driven to rotate, and the outer beam (3) is driven to move linearly synchronously.

4. The single-degree-of-freedom variant UAV driving mechanism capable of realizing synchronous conformational change according to claim 1, characterized in that: The surface of the outer transmission shaft (72) is provided with at least one second spiral groove, the second spiral groove has a rotation direction opposite to that of the first spiral groove, a second slider is slidably accommodated in the second spiral groove, and the second slider is fixedly mounted in an outer sleeve (82) sleeved on the outer transmission shaft (72), and the end of the outer beam (3) is sleeved on the outer sleeve (82) and is fixedly connected to the outer sleeve (82); thereby, the outer transmission shaft (72) is driven to rotate during the linear motion of the outer beam (3), and the inner transmission shaft (41) and the outer transmission shaft (42) are synchronously rotated in opposite directions. Finally, during the upward folding process of the inner wing, the outer wing can be made to move upward in a horizontal direction.

5. The single-degree-of-freedom variant UAV driving mechanism capable of realizing synchronous conformational change according to claim 1, characterized in that: The outer carbon tube (72) passes through the outer wing, and the two are clearance-matched at the penetration position. A mounting plate that fits the inner end surface of the inner wing is fixedly installed at the end position of the outer carbon tube (72). A clamping shaft (91) that passes through the mounting plate is fixedly installed on the inner end surface of the inner wing. A plug plate (92) that is arranged perpendicular to the clamping shaft (91) is slidably connected on the surface of the mounting plate. An annular slot is provided on the surface of the clamping shaft (91), and a plug opening that is adapted to the annular slot is opened on the plug plate (92).

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