A UAV with a multi-wing synchronous folding mechanism

Abstract

The present invention discloses a UAV with a multi-wing synchronous folding mechanism, including a body and a plurality of propellers, the body is a cylindrical rotating body, the propellers are evenly distributed around the circumference of the body center line, the propellers are connected to the body surface through arms, and the propellers are jet engines or propellers. There are three propellers in total, and the connection between the arms and the body is a rotatable active connection, and the rotation axis of the arms is perpendicular to the body center line and intersects with the body center line. The UAV also includes a plurality of tail wings, which are evenly distributed around the body tail, and the number of tail wings is the same as the number of propellers. A folding mechanism is provided at the root of the tail wing for extending or retracting the tail wing. The attitude changes of the UAV's level flight, steering, and pitch adjustment can be completed by the emission angles and outputs of each propeller, and the UAV's rotation attitude changes are also added. The combination is flexible and changeable, and very complex flight actions can be completed by simple control.

Description

Technical Field

[0001] The invention relates to the field of unmanned aerial vehicles, in particular to a unmanned aerial vehicle with a multi-wing synchronous folding mechanism. Background Art

[0002] Drones are being used in more and more areas.

[0003] High-speed civilian and military drones basically use high-power propellers as power or fuel-powered jet engines as power. These drones basically use the traditional take-off method of civil airliners and fighter jets. The power of the propellers is all converted into the forward speed of the fuselage and flies through the interaction between the wings and the air. These aircraft require a long runway to obtain sufficient take-off speed.

[0004] In the prior art, there is no high-speed UAV that can achieve vertical take-off and landing similar to a helicopter. Most vertical take-off and landing UAVs have propellers arranged in the form of a helicopter. The power provided by this arrangement cannot allow the UAV to achieve a large horizontal flight speed. Summary of the invention

[0005] The object of the present invention is to provide a UAV with a multi-wing synchronous folding mechanism to solve the problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The utility model discloses an unmanned aerial vehicle with a multi-wing synchronous folding mechanism, comprising an airframe and a plurality of propellers. The airframe is a cylindrical rotating body, the propellers are evenly distributed around the circumference of the airframe center line, and the propellers are connected to the surface of the airframe through airframe arms.

[0008] The thrusters are arranged radially and evenly distributed around the circumference. The thrusters are jet engines or propellers. The air outlet direction of the thrusters is toward the rear of the fuselage. When all thrusters eject air backwards together, the fuselage in a vertical posture can take off into the air. After entering the air vertically, whether it is through the adjustable angle of the wing to change the flight angle or by changing the jet angle of the nozzle, the drone will eventually become a conventional horizontal flight. For high-speed jet drones, the vertical take-off method greatly reduces the take-off conditions of the drone and expands the application occasions of the drone.

[0009] Furthermore, there are three thrusters, namely the first thruster, the second thruster and the third thruster. The posture during horizontal flight is taken as the standard posture. The thruster at the highest point is defined as the first thruster, the thruster on the left side relative to the forward direction is defined as the second thruster, and the thruster on the right side relative to the forward direction is defined as the third thruster. The body coordinate system is defined in this posture, with the forward direction as X, the direction perpendicular to the X direction on the horizontal plane as Y, and the vertical direction as Z.

[0010] Furthermore, the connection between the machine arm and the machine body is a rotatable movable connection, and the rotation axis of the machine arm is perpendicular to the center line of the machine body and intersects with the center line of the machine body.

[0011] The three adjustable-angle propellers operate simultaneously, which can realize the flight, steering, pitching and other actions of the drone. The drone is in a normal horizontal flight state. At this time, the angle of the first propeller is facing forward, and the angles of the second and third propellers are slightly upward. The forces given to the body by the propellers are recorded as F2, F3, and F4 respectively. The overall gravity of the drone is recorded as G, the angle between F3 and X is recorded as θ3, and the angle between F4 and X is recorded as θ4. F3z= F3*sinθ3, F3x= F3*cosθ3, F4z= F4*sinθ4, F4x= F4*cosθ4,

[0012] The force balance has the following conditions:

[0013] 1. The resultant force of F3z and F4z is equal to G, that is: F3z+F4z=G;

[0014] 2. The torque difference between F3z and F4z relative to the body is zero.

[0015] That is: F3z*0.866L= F4z*0.866L, this is the balance of rotation torque, when the balance condition is reached, the body will not rotate;

[0016] 3. The moment of the combined force of F3x and F4x on the center of gravity from below is equal to the moment of F2 on the center of gravity from above, that is: F3x*0.5L+F4x*0.5L=F2*L; this is the pitch moment balance. After the balance condition is reached, the body will not pitch;

[0017] 4. The moments of F3x and F4x about the center of gravity are equal.

[0018] That is: F3x*0.866 L= F4x *0.866L, this is the steering torque balance. After reaching the balance condition, the body will not deflect in the horizontal direction;

[0019] The above four forces and torque balances are necessary conditions for horizontal straight flight. The rest are: the resultant force of F2, F4x, and F3x is the forward force of the drone. When the resultant force is equal to the flight resistance during forward movement, the drone flies at a constant speed. When it is higher than the resistance, the drone accelerates, and when it is lower than the resistance, the drone decelerates.

[0020] Taking the horizontal turning of the UAV as an example, the steering principle is discussed. The arm of the third thruster is rotated by an angle so that its output forms an angle θ4 with X. The fourth item in the force balance condition changes: F4x*0.866L>F3x*0.866L, and the body turns to the left. The remaining force and torque balance conditions can be maintained unchanged by changing the output size of each thruster, specifically: F4 increases (F4z remains unchanged), F3 remains unchanged, and F2 increases (F3x*0.5L+F4x'*0.5L=F2'*L). After the turning is completed, θ4 is readjusted to restore it to be equal to θ3.

[0021] When the UAV rotates, it mainly changes F3z and F4z to make them have a difference to provide rotation torque; when the UAV pitches, it mainly changes the size of F2, F2 becomes larger to enter a dive posture, and F2 becomes smaller to enter a pitch-up climbing posture; when the UAV keeps the center line horizontal and performs parallel ascent or fall, the sizes of F3z and F4z are adjusted at the same time; various attitude changes can be combined accordingly and decomposed into the above four basic changes, and force analysis is performed to decide how to make adjustments. The flight status can be identified by the gyroscope installed in the fuselage.

[0022] In addition, the synchronous operation of the three thrusters has another effect, which is that it can maintain the stability of the fuselage during vertical lift. The three thrusters spray in an oblique direction, and the forces provided by the three thrusters are combined into a vertical lift to balance gravity. Each of them has three components that allow the drone to rotate. The drone takes off in a spiral manner, just like a bullet spiraling forward and a gyroscope spinning on its own. This eliminates possible uneven weight distribution on the components, making it easier for the head of the fuselage to break through the air and maintain the stability of the fuselage's ascent. Using this method as a means of ascent, the thruster mounting arms can be made shorter.

[0023] Furthermore, the drone also includes a number of tail wings, which are evenly distributed around the tail of the fuselage. The number of tail wings is the same as the number of propellers, and a folding mechanism is provided at the root of the tail wing for extending or retracting the tail wing. The tail wing plays a role in stabilizing the wake and preventing self-rotation when the drone is flying horizontally, but the addition of the tail wing will hinder the aforementioned spiral takeoff method, because during this takeoff process, the surface of the tail wing is facing the direction of the airflow, so the resistance will not only increase significantly, but also disturb the tail airflow, which is very likely to overturn. Therefore, the tail wing should be folded when the drone takes off or lands in a spiral line.

[0024] Furthermore, the folding mechanism includes a connecting rod, a sliding screw, and a driving nut. A sheet-shaped groove-shaped folding bin is provided at the rear of the body, and a circular hole-shaped driving slot is provided in the center of the rear of the body. One end of the tail wing is hinged to the root of one end of the folding bin, and the bottom of the other end of the tail wing is hinged to the connecting rod. The other end of the connecting rod is hinged to the end of the sliding screw. The sliding screw is arranged in the driving slot, and the driving nut is also arranged in the driving slot and is threadedly connected to one end of the sliding screw. The driving nut has an active rotational power.

[0025] The present invention realizes the retraction and extension of the tail wing through the structure of a "slider rocker", which is a state where the tail wing is folded. When the vertical take-off process is completed and the level flight stage is entered, the driving nut rotates, and the sliding screw cannot rotate along with the flight because its end is connected to multiple connecting rods, and can only perform translational motion to form a screw structure. The backward sliding screw pushes up the connecting rod, and the connecting rod pushes the tail wing out of the folding compartment. When the tail wing needs to be retracted, it is only necessary to reverse the driving nut and move the sliding screw forward.

[0026] As an optimization, there is also an obstacle-breaking pin on the head of the fuselage, which is located on the center line of the fuselage. The obstacle-breaking pin is suitable for the high-speed flight state of this drone. The propeller uses a high-thrust jet engine to enable the drone to obtain high-speed flight capabilities. The obstacle-breaking pin pierces the sound barrier and maintains the stability of the drone.

[0027] Furthermore, the tail of the fuselage is also provided with a take-off and landing wheel set, which includes a connecting pivot, a wheel axle and a number of sliding wheels. The connecting pivot is fixed at the tail of the fuselage, the wheel axle is bent, one end of the wheel axle is connected to the connecting pivot, and the other end of the wheel axle extends radially with the center line of the fuselage as the axis and a sliding wheel is arranged at the end. In the initial stage of spiral takeoff and the final stage of spiral landing, there will be a contact process between the tail of the fuselage and the landing platform. The take-off and landing wheel set acts as an intermediary to come into contact with the ground during takeoff and landing, and the rotating sliding wheels convert friction into rolling friction.

[0028] As an optimization, the take-off and landing wheel set also includes a tightening spring. The connection between the wheel axle and the connecting pivot is a ball joint bearing connection. The tightening spring is connected to the bend of each wheel axle. When landing, there is an impact force, the wheel axle deforms appropriately, the three sliding wheels expand outward, and the contact point of the sliding wheel tire tilts outward. The tightening spring resists the expansion tendency and helps to recover.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention arranges three propellers on the surface of the fuselage in a circumferentially evenly distributed installation form, and each of the three propellers can rotate around an axis perpendicular to and intersecting the center line of the fuselage, so that the attitude changes of the UAV such as level flight, turning, and pitch adjustment can be completed through the emission angle and output of each propeller, and the attitude change of the UAV's rotation is also added. The combination is flexible and changeable, and very complex flight movements can be completed through simple control. Combined with the auxiliary devices and even combat weapons of the UAV, it can become a military UAV through relevant modifications; the vertical take-off and landing method completely eliminates the take-off site restrictions of high-speed UAVs; the spiral take-off and landing formed by self-rotation during vertical take-off and landing greatly improves the take-off and landing stability and saves the length of the propeller arm; the foldable tail wing can be extended and retracted as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0031] Figure 1 It is a schematic diagram of the appearance of the present invention;

[0032] Figure 2 This is a force analysis diagram of the present invention during vertical takeoff;

[0033] Figure 3 It is a force analysis diagram on the front view of the present invention when it is flying horizontally;

[0034] Figure 4 This is a schematic diagram of the propeller arrangement of the present invention as viewed from the head of the fuselage;

[0035] Figure 5 This is a force analysis diagram of the present invention during constant speed horizontal straight flight under a three-dimensional viewing angle;

[0036] Figure 6 This is a force analysis diagram of the present invention when turning horizontally from a three-dimensional perspective;

[0037] Figure 7 It is a structural diagram of the folding mechanism of the present invention and the tail wing when they are in the stowed position;

[0038] Figure 8 It is a structural diagram of the folding mechanism of the present invention and the tail wing when they are in the unfolded position;

[0039] Fig. 9 It is a three-dimensional schematic diagram of the take-off and landing wheel set of the present invention.

[0040] In the figure: 1-body, 11-folding compartment, 12-driving slide, 2-first propeller, 3-second propeller, 4-third propeller, 5-tail, 6-folding mechanism, 61-connecting rod, 62-sliding screw, 63-driving nut, 7-obstacle-breaking needle, 81-connecting pivot, 82-tightening spring, 83-axle, 84-sliding wheel. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] like Figure 1 As shown, a UAV with a multi-wing synchronous folding mechanism includes a body 1 and a plurality of propellers. The body 1 is a cylindrical rotating body, and the propellers are evenly distributed around the circumference of the center line of the body 1. The propellers are connected to the surface of the body 1 through arms.

[0043] The thrusters are arranged radially and evenly distributed around the circumference. The thrusters are jet engines or propellers. The thrusters' air outlet direction is toward the rear of the fuselage 1. When all thrusters eject air backwards together, the fuselage 1 in a vertical posture can take off into the air. After entering the air vertically, whether the flight angle is changed by the adjustable angle wing or by changing the jet angle of the nozzle, the drone can eventually become a conventional horizontal flight. For high-speed jet drones, the vertical take-off method greatly reduces the take-off conditions of the drone and expands the application occasions of the drone.

[0044] like Figures 1 to 4 As shown, there are three thrusters, namely the first thruster 2, the second thruster 3 and the third thruster 4. The posture during horizontal flight is taken as the standard posture. The thruster at the highest point is defined as the first thruster 2, the thruster on the left side relative to the forward direction is defined as the second thruster 3, and the thruster on the right side relative to the forward direction is defined as the third thruster 4. The body coordinate system is defined in this posture, as shown in FIG. Figures 5 and 6 As shown, the forward direction is X, the direction perpendicular to the X direction on the horizontal plane is Y, and the vertical direction is Z;

[0045] like Figure 1 As shown, the connection between the machine arm and the machine body 1 is a rotatable movable connection, and the rotation axis of the machine arm is perpendicular to the center line of the machine body 1 and intersects with the center line of the machine body 1.

[0046] The three adjustable-angle propellers operate simultaneously, which can realize the flight, steering, pitching and other actions of the drone. Figure 3 , 5 As shown, the UAV is in a normal horizontal flight state. At this time, the first propeller 2 is facing forward, the second propeller 3 and the third propeller 4 are facing slightly upward, and the forces given to the body 1 by the propellers are recorded as F2, F3, and F4 respectively. The overall gravity of the UAV is recorded as G, the angle between F3 and X is recorded as θ3, the angle between F4 and X is recorded as θ4, F3z= F3*sinθ3, F3x= F3*cosθ3, F4z= F4*sinθ4, F4x= F4*cosθ4,

[0047] The force balance has the following conditions:

[0048] 1. The resultant force of F3z and F4z is equal to G, that is: F3z+F4z=G;

[0049] 2. The torque difference between F3z and F4z relative to the body 1 is zero,

[0050] That is: F3z*0.866L= F4z*0.866L, this is the balance of the rotation torque, when the balance condition is reached, the body 1 will not rotate;

[0051] 3. The moment of the combined force of F3x and F4x on the center of gravity from below is equal to the moment of F2 on the center of gravity from above, that is: F3x*0.5L+F4x*0.5L=F2*L; this is the pitch moment balance. After the balance condition is reached, the body 1 will not pitch;

[0052] 4. The moments of F3x and F4x about the center of gravity are equal.

[0053] That is: F3x*0.866 L= F4x *0.866L, this is the steering torque balance. After reaching the balance condition, the body 1 will not deflect in the horizontal direction;

[0054] The above four forces and torque balances are necessary conditions for horizontal straight flight. The rest are: the resultant force of F2, F4x, and F3x is the forward force of the drone. When the resultant force is equal to the flight resistance during forward movement, the drone flies at a constant speed. When it is higher than the resistance, the drone accelerates, and when it is lower than the resistance, the drone decelerates.

[0055] Taking the horizontal turning of a UAV as an example, the steering principle is discussed. Figure 6As shown, the arm of the third thruster 4 is rotated by an angle so that its output forms an angle θ4 with X, and the lower 4 items in the force balance condition change: F4x*0.866L>F3x*0.866L, and the body 1 turns to the left. The remaining force and torque balance conditions can be maintained unchanged by changing the output size of each thruster, specifically: F4 increases (F4z remains unchanged), F3 remains unchanged, and F2 increases (F3x*0.5L+F4x'*0.5L=F2'*L). After the turn is completed, θ4 is readjusted to restore it to be equal to θ3.

[0056] When the drone rotates, it is mainly necessary to change F3z and F4z to make them have a difference to provide the rotation torque; when the drone pitches, it is mainly necessary to change the size of F2, F2 becomes larger to enter the dive attitude, and F2 becomes smaller to enter the pitch climbing attitude; when the drone keeps the centerline horizontal and performs parallel ascent or fall, the sizes of F3z and F4z are adjusted at the same time; various attitude changes can be combined accordingly, decomposed into the above four basic changes and refer to Figure 5 or Figure 6 A force analysis is performed to determine how to make adjustments, and the flight status can be identified by a gyroscope installed in the body 1.

[0057] In addition, the synchronous operation of the three thrusters can also maintain the stability of the body 1 during vertical ascent and descent, such as Figure 1 , 2 As shown, the three thrusters spray in an oblique direction, and the forces provided by the three thrusters are combined into a vertical lift to balance the gravity. Each thruster has three components to make the drone rotate. The take-off of the drone is a spiral rise, just like the spiral advance of a bullet and the rotation of a gyroscope. This eliminates the uneven weight distribution that may exist on the components, facilitates the head of the body 1 to break through the air, and maintains the stability of the body 1 as it rises. In this way, the mounting arm of the thruster can be made shorter ( Figure 4 length L in the middle).

[0058] like Figure 1 As shown, the UAV further includes a plurality of tail wings 5, which are evenly distributed around the tail of the body 1. The number of tail wings 5 ​​is the same as the number of propellers. A folding mechanism 6 is provided at the root of the tail wing 5 for extending or retracting the tail wing 5. The tail wing 5 plays a role in stabilizing the wake and preventing self-rotation when the UAV is flying horizontally. However, the addition of the tail wing 5 will hinder the aforementioned spiral takeoff method, because in this takeoff process, the surface of the tail wing 5 faces the direction of the airflow, so the resistance is significantly increased, and the tail airflow is disturbed, which is very likely to overturn. Therefore, the tail wing 5 should be folded when the UAV takes off or lands in a spiral line.

[0059] like Figure 7As shown, the folding mechanism 6 includes a connecting rod 61, a sliding screw 62, and a driving nut 63. A sheet-shaped groove-shaped folding bin 11 is provided at the rear of the body 1, and a circular hole-shaped driving slide groove 12 is provided in the center of the rear of the body 1. One end of the tail wing 5 is hinged to the root of one end of the folding bin 11, and the other end of the tail wing 5 is hinged to the connecting rod 61 at the bottom, and the other end of the connecting rod 61 is hinged to the end of the sliding screw 62. The sliding screw 62 is arranged in the driving slide groove 12, and the driving nut 63 is also arranged in the driving slide groove 12 and is threadedly connected with one end of the sliding screw 62. The driving nut 63 has an active rotational power.

[0060] The present invention realizes the retraction and extension of the tail wing 5 through the structure of the "slider rocker", such as Figure 7 As shown, the tail 5 is in the folded state. When the vertical take-off process is completed and the horizontal flight stage is entered, the driving nut 63 rotates. Since the sliding screw 62 is connected to multiple connecting rods 61 at its end, it cannot rotate with it and can only move in translation to form a screw structure. The sliding screw 62 moves backward to push up the connecting rod 61, and the connecting rod 61 pushes the tail 5 out of the folding compartment 11 to reach the horizontal flight stage. Figure 8 When the tail wing 5 needs to be retracted, it is only necessary to reverse the drive nut 63 and move the sliding screw 62 forward.

[0061] like Figure 3 As shown, the head of the body 1 is also provided with an obstacle-breaking pin 7, which is located on the center line of the body 1. The obstacle-breaking pin 7 is suitable for the high-speed flight state of the UAV. The propeller uses a high-thrust jet engine to enable the UAV to obtain high-speed flight capability. The obstacle-breaking pin 7 pierces the sound barrier to maintain the stability of the UAV.

[0062] like Fig. 9 As shown, the tail of the fuselage 1 is also provided with a take-off and landing wheel set, which includes a connecting pivot 81, a wheel axle 83 and a plurality of sliding wheels 84. The connecting pivot 81 is fixed at the tail of the fuselage 1, the wheel axle 83 is bent, one end of the wheel axle 83 is connected to the connecting pivot 81, and the other end of the wheel axle 83 radially extends with the center line of the fuselage 1 as the axis and a sliding wheel 84 is arranged at the end. In the initial stage of spiral takeoff and the final stage of spiral landing, there will be a contact process between the tail of the fuselage 1 and the landing platform. The take-off and landing wheel set acts as an intermediary to contact the ground during takeoff and landing, and the rotating sliding wheels 84 convert friction into rolling friction.

[0063] like Fig. 9 As shown, the take-off and landing wheel set also includes a tightening spring 82, the connection between the wheel axle 83 and the connecting pivot 81 is a ball joint bearing connection, and the tightening spring 82 is respectively connected to the bending part of each wheel axle 83. When landing, there is an impact force, the wheel axle 83 is appropriately deformed, the three sliding wheels 84 expand outward, and the contact part of the sliding wheel 84 tire tilts outward, and the tightening spring 82 resists the expansion tendency and helps to recover.

[0064] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A drone with a multi-wing synchronous folding mechanism, characterized in that: The drone comprises a body (1) and a plurality of propellers, the body (1) being a cylindrical rotating body, the propellers being evenly distributed around the circumference of the center line of the body (1), and the propellers being connected to the surface of the body (1) via arms; There are three thrusters in total, and the connection between the arm and the body (1) is a rotatable movable connection, and the rotation axis of the arm is perpendicular to the center line of the body (1) and intersects with the center line of the body (1); When the propellers fly horizontally, it is recorded as the standard attitude, and the propeller at the highest point is defined as the first propeller (2), the propeller on the left side relative to the forward direction is defined as the second propeller (3), and the propeller on the right side relative to the forward direction is defined as the third propeller (4), and the body coordinate system is defined in this attitude, with the forward direction as X, the direction perpendicular to the X direction on the horizontal plane as Y, and the vertical direction as Z; The propulsion forces of the first propeller (2), the second propeller (3) and the third propeller (4) are respectively denoted as F2, F3 and F4, the angle between F3 and X is denoted as θ3, the angle between F4 and X is denoted as θ4, F3z=F3*sinθ3, F3x=F3*cosθ3, F4z=F4*sinθ4, F4x=F4*cosθ4, and the overall gravity of the drone is denoted as G; The aircraft's horizontal flight, pitch, and turning movements are adjusted by the combined thrusts F2, F3, F4, θ3, and θ4: When the drone maintains horizontal flight: F3z+F4z=G; F3z=F4z, (F3x+F4x)=2*F2, F3x=F4x; When the drone needs to tilt up to climb: (F3z+F4z)=G, F3z=F4z, (F3x+F4x)>(2*F2), F3x=F4x; When the drone needs to dive down: (F3z+F4z)=G, F3z=F4z, (F3x+F4x)<(2*F2), F3x=F4x; When the drone needs to turn left horizontally: (F3z+F4z)=G, F3z=F4z, (F3x+F4x)=(2*F2), F3x <F4x; The propeller is a jet engine or a propeller, and the air outlet direction of the propeller is toward the rear of the fuselage; the UAV rotates when taking off.

2. The UAV with a multi-wing synchronous folding mechanism according to claim 1, characterized in that: The head of the machine body (1) is also provided with an obstacle-clearing needle (7), and the obstacle-clearing needle (7) is located on the center line of the machine body (1).

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