KR20120032788A - Unmanned air vehicle and bending stiffness increasing method of unmanned air vehicle wing by tension - Google Patents

Abstract

PURPOSE: An unmanned air craft and a method for enhancing the bending strength of an unmanned air craft wing by tension are provided to actively control the bending strength of an unmanned air craft wing using additional thrust stretching the wing to both sides, thereby preventing loss and damage caused by local turbulence. CONSTITUTION: An unmanned air craft(1) comprises a wing(10) which is made of a membrane and a tension generator(20) which is installed on both ends of the wing and stretches the wind in a longitudinal direction.

Description

Unmanned air vehicle and bending stiffness increasing method of unmanned air vehicle wing by tension}

The present invention relates to a method of increasing bending rigidity through tension of an unmanned aerial vehicle and an unmanned aerial vehicle, and in more detail, by tensioning the wing of an unmanned aerial vehicle using thrust or force by surrounding flow, compared to a case where there is no tension. It is possible to secure greater bending stiffness to withstand greater bending stresses, or through the tensioning of unmanned and unmanned aerial vehicle wings that utilize thin membranes that are not resistant to bending stresses to secure bending stiffness. The present invention relates to a method of increasing bending stiffness.

Recently, as information becomes important in various situations such as war, intelligence satellites and reconnaissance planes are continuously developed and manufactured. In the case of satellites, geostationary satellites are too high for satellites to obtain sufficient information, and low-orbit satellites are often difficult to use when they need to keep moving.

Therefore, the development and manufacture of high-altitude long-endurance drones continues to ensure accurate reconnaissance activities where and when they are needed.

However, high altitude long-term drones developed to date have a short flight time of only 36 hours and enormous operating costs, and studies to overcome them are continuing.

In addition, due to the recent climate change agreements caused by global warming, there is a craze to use green energy instead of fossil fuels to reduce greenhouse gases worldwide. In particular, in the aviation sector, air pollution is a very big problem because of the large amount of fuel consumed by the propulsion system.

However, in the aviation sector, thrust per unit weight is important, so it is very difficult to replace green energy instead of high-efficiency fossil fuels.

Despite these difficulties, unmanned aerial vehicles have been steadily attempting to utilize green energy, solar energy, and are very efficient in that they can obtain energy sources from the sun during flight due to the characteristics of long-term drones. .

On the other hand, the power supplied from the solar energy is limited, the amount varies depending on the area of the solar cell mounted on the wing of the unmanned aerial vehicle.

Since the lift of the aircraft is proportional to the square of the flight speed, the density of the air and the wing area, the wing area must be further increased in order for the lift of the aircraft to be constant at high altitudes with low air density.

However, as the wing length increases, the bending stress acting on the wing root increases, and thus, high rigidity structural materials or additional structural design are required to secure bending stiffness. In addition, a large deflection may occur at the wing tip, and thus, there is a problem that aeroelastic problems may further appear, such as aerodynamic effects of the wing being changed.

For example, NASA's Helios solar energy-based high altitude long-term drone has a wingspan of approximately 75 meters and a large aspect ratio of the wings due to local turbulence. Stalls occurred in some of the wings, so they could not endure large bending stresses, and the wings broke and crashed.

Therefore, there is a need for development of a method of increasing the length of the wing of the aircraft while increasing the stiffness of the wing in addition to the passive method of increasing the stiffness by adding the structural material or the length of the wing using a composite material.

The present invention has been made to solve the above problems, the object of the present invention is to further use the structural material by actively adjusting the bending stiffness of the wing through the additional thrust to tension the wing of the unmanned aerial vehicle on both sides The present invention provides a method of increasing bending rigidity through tension of an unmanned aerial vehicle and an unmanned aerial vehicle wing capable of generating a lift necessary for the unmanned aerial vehicle while preventing stalling and damage due to local turbulence without reinforcing the structure.

In addition, an object of the present invention is to actively control the bending stiffness of the thin film wings through the tensile force and to generate a lift by controlling the shape, it is possible to reduce the weight of the unmanned aerial vehicle and increase the area of the wing without a sharp increase in weight It is possible to provide a method of increasing the bending rigidity through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wing that can maintain sufficient lift even at high altitude.

In the unmanned aerial vehicle 1 of the present invention having a wing 10, the unmanned aerial vehicle 1 is provided at both ends in the longitudinal direction of the wing 10, respectively, the wing 10 in the longitudinal direction It characterized in that it is formed including a tensile force generating unit 20 to tension.

In addition, the wing 10 of the unmanned aerial vehicle 1 is characterized in that consisting of a film.

In addition, the wing 10 is characterized in that the fabric is made of synthetic resin or air is not permeable so that the permanent deformation and breakage due to the bending stress applied during the flight.

In addition, the unmanned aerial vehicle 1 has a tension force generated in the direction in which the auxiliary wing 30 and the wing 10 is tensioned on the other side opposite to one side of the tension force generation unit 20 to which the wing 10 is connected. At least one of the propeller to be characterized in that it is provided.

In addition, the unmanned aerial vehicle 1 is characterized in that the rudder 40 is further provided on the tensile force generating unit 20 or the auxiliary wing 30 to utilize the force received from the surrounding flow as the tensile force.

In addition, the tensile force generating unit 20 is characterized in that the cross section in the longitudinal direction is a flying fuselage of the airfoil shape so that the tensile force generating unit 20 receives the force in the direction to generate the tensile force continuously.

In addition, the wing 10 is characterized in that it is formed in the form of bladder so that the gas is injected.

In addition, the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle wing (a) the tension force generating unit 20 by applying a force outward in the longitudinal direction of the wing 10 to tension the wing 10 Characterized in that it comprises a.

In addition, the method of increasing the bending rigidity through the tension of the unmanned aerial vehicle wing (b) by adjusting the angle of the rudder 40 by the force applied to the rudder 40 from the surrounding flow to tension the wing 10 And controlling the direction of the force to act as a force to make.

In addition, the method of increasing the bending rigidity through the tension of the unmanned aerial vehicle wing (c) is characterized in that it comprises the step of injecting gas into the inner space of the wing 10 formed in the form of air sacs.

The method of increasing the bending stiffness through tensioning of the unmanned aerial vehicle and the unmanned aerial vehicle wing of the present invention facilitates the further use of structural materials by actively controlling the bending stiffness of the wing through additional thrust that tensions the wing of the unmanned aerial vehicle on both sides. Even without reinforcing through the structure, there is an advantage in that lifting force required for the unmanned aerial vehicle can be generated while preventing stalling and damage due to local turbulence.

In addition, the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wings of the present invention by actively controlling the bending stiffness through the tensile force of the thin film wings and by controlling the shape to generate lift, It is possible to reduce the weight and increase the wing area without a sudden increase in weight, and thus has the advantage of maintaining sufficient lift even at high altitudes.

In addition, the method of increasing the bending rigidity through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wing of the present invention is to mount more solar cells in the unmanned aerial vehicle that uses solar energy as an energy source by mounting the solar cell on the wing. In order to increase the size of the wing, since the wing is made of a thin film to increase the area of the wing without reinforcing the structure, there is an advantage that the unmanned aerial vehicle using solar energy can be applied to allow long-term flight at high altitude.

1 is a perspective view schematically showing the wings of the present invention.
Figure 2 is a perspective view schematically showing an unmanned aerial vehicle of the present invention.
Figure 3 is a perspective view schematically showing another wing of the present invention.
4 is a cross-sectional view showing the geometrical parameters of a typical wing cross section.
5 is a partial perspective view schematically showing another unmanned aerial vehicle of the present invention.
Figure 6 is a perspective view schematically showing another unmanned aerial vehicle of the present invention.

Hereinafter, a method of increasing bending stiffness through tension of an unmanned aerial vehicle and an unmanned aerial vehicle wing of the present invention having the features as described above will be described in detail with reference to the accompanying drawings.

1 is a perspective view schematically showing a wing of the present invention, Figure 2 is a perspective view schematically showing an unmanned aerial vehicle of the present invention, Figure 3 is a perspective view schematically showing another wing of the present invention, Figure 4 is a general vehicle 5 is a partial perspective view schematically showing another unmanned aerial vehicle of the present invention, and FIG. 6 is a perspective view schematically showing another unmanned aerial vehicle of the present invention.

According to the present invention, in the unmanned aerial vehicle 1 having a wing, each of the wings 10 is provided at both ends in the longitudinal direction, and includes a tension force generating unit 20 for tensioning the wing 10 in the longitudinal direction. It relates to an unmanned aerial vehicle (1) characterized in that.

The wing 10 of the unmanned aerial vehicle 1 may be formed of a film, and the tensile force generating unit 20 has a cross section in the longitudinal direction such that the tensile force generating unit 20 receives a force in a direction in which tensile force is continuously generated. It may be a flying fuselage of this airfoil form.

In addition, the unmanned aerial vehicle 1 is provided with at least one of the auxiliary wing 30 and the propeller on the other side opposite to one side of the tensile force generating unit 20 is connected to the wing 10 as shown in FIG. Can be.

The propeller is installed on the tensile force generating unit 20 in the direction in which the wing 10 is tensioned, so that the wing 10 can be tensioned.

Accordingly, the wing 10 may be tensioned by applying a tensile force in the longitudinal direction and the outward direction of the wing 10 by the thrust of the flying fuselage.

At this time, the wing 10 is made of a synthetic material such as nylon or a non-permeable cloth such as nylon that can be used to make a parachute or a parafoil so that permanent deformation and breakdown do not occur due to bending stress applied during the flight. Can be made.

The unmanned aerial vehicle 1 may further include a rudder 40 in the tensile force generating unit 20 or the auxiliary wing 30 so that the force received from the surrounding flow may be used as the tensile force, and the wing 10 may have an air bladder. It may be formed in a shape and gas may be injected therein.

Meanwhile, a method of increasing bending stiffness by tensioning an unmanned aerial vehicle wing as described above may include (a) tensioning the wing 10 by applying a force outwardly in the longitudinal direction of the wing 10 by the tension force generation unit 20. step; (b) adjusting the direction of the force such that the force applied to the rudder 40 from the surrounding flow acts as a force to tension the blade 10 by adjusting the angle of the rudder 40; (c) injecting gas into the inner space of the wing 10 formed in the form of an air sac; It includes, and may be any one of steps (a), (a) and (b), (a) and (c), (a) and (b) and (c).

A method of increasing the bending stiffness through the tension of the unmanned aerial vehicle wing as described above will be described in detail in Examples 1 to 3.

Example 1

Embodiment 1 of the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle wing (a) the tension force generating portion 20 to apply the force outward in the longitudinal direction of the wing 10 to tension the wing 10 It comprises the step of.

Referring to Figures 1 to 2, the conventional blade 10 and the blade 10 in the form of a thin film as described above is applied to the tensile force applied by the thrust and peripheral flow by the tension generating unit 20. By being stretched, the rigidity that can withstand bending stress can be increased.

The tensile force generating unit 20, that is, the flying fuselage is provided at both ends in the longitudinal direction of the wing 10 to control the wing 10 made of a thin film to have a camber shape, the wing 10 Tension to allow for lift to be generated.

At this time, the flying fuselage is provided with a propeller in the direction in which the wing 10 is tensioned may be a tensile force generated by the operation of the propeller.

Referring to Figure 4, summarized by the formula to support the method of increasing the bending rigidity of the wing as described above,

은 [수학식 1]과 같이 주어진다.Lift per wing unit length from typical aircraft wings

Is given by Equation 1.

[Equation 1]

는 공기밀도,

는 날개에 입사하는 유동의 속도,

는 시위길이,

은 단면양력계수이다. 상술한 바와 같이 캠버 형상을 가지는 얇은 막 형태의 날개는 단면양력계수

을 가지며, 얇은 날개 이론(thin airfoil theory)에 따라(날개의 두께

이므로) [수학식 2] 를 얻을 수 있다.only,

Is the air density,

Is the velocity of flow entering the wing,

The length of the protest,

Is the section lift coefficient. As described above, the thin-film wing having a camber shape has a cross-sectional lift coefficient

According to the thin airfoil theory (wing thickness

Equation 2 can be obtained.

[Equation 2]

는 받음각(angle of attack),

는 영양력각(angle of zero lift),

는 시위선

로부터 평균 캠버선의 높이(얇은 막 형태의 날개이므로 날개의 위치),

는 날개 앞전에서의 위치이다. 날개 단면(날개 익형, Airfoil)의 기하학적 변수들을 도 3에 도식화하였다.only,

Is the angle of attack,

Is the angle of zero lift,

Protesters

Height of the average camber wire (as it is a wing of the thin film form, position of the wing),

Is the position in front of the wing. The geometrical parameters of the wing cross section (wing airfoil) are plotted in FIG. 3.

Therefore, the section lift coefficient is determined by the angle of attack and the shape of the camber. Therefore, even thin-film wings can achieve the same lift as regular wings if proper angle of attack, camber shape and angle of attack are properly controlled. However, in the case of general type wing, even if lift is generated, the change in wing shape does not have a big influence on lift, but in the case of thin film, when lift is lifted to lift the aircraft, the shape of the wing is greatly deformed and it is difficult to generate the desired lift sufficiently. Therefore, in the present invention, the tensile force is utilized to have sufficient bending rigidity even in a thin film.

Since the mathematical derivation and result formula for the actual wing shape is very complex, the following results can be obtained for a simply supported rectangular plate.

, 세로의 길이가

, 굽힘 강성(Flexural rigidity)가

인 판(plate)에 수직하게 단위 면적당

의 힘이 가해지고 가로 방향으로 단위 길이당

의 인장력이 작용할 때 판의 수직 변위

는 [수학식 3]과 같다.The length of the width

, The vertical length

, Flexural rigidity

Per unit area perpendicular to the plate

Force per unit length in the horizontal direction

Displacement of the plate when the tensile force of

Is the same as [Equation 3].

&Quot; (3) "

가 증가함에 따라 판의 수직 변위는 감소하게 되어 굽힘 강성이 증가한다.Thus tensile force

As increases the vertical displacement of the plate decreases, increasing the bending stiffness.

Equation 3 holds only for isotropic elastic bodies, but the principle is the same for non-linear solids. Therefore, by applying an appropriate tensile force to the blade, the bending rigidity can be increased to reduce the deformation of the wing, and thus a thin film-shaped wing can be used as a lift wing.

Example 2

Embodiment 2 of the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle wing (a) the tension force generating portion 20 is applied to the outside in the longitudinal direction of the wing 10 to tension the wing 10 Making a step; (c) injecting gas into the inner space of the wing 10 formed in the form of an air sac; It includes.

Referring to FIG. 3, in Example 2, a wing 10 formed of a thin film of Example 1 is formed in a bladder shape, and gas is injected into an inner space of the wing 10.

가 가해져 원형을 유지하고자 하는 힘과 복원력이 존재하게 되며, 기체가 주입된 상기 날개(10)에 인장력

가 가해지면 굽힘 강성이 증대되어 실시 예1의 날개(10)보다 작은 인장력으로 동일한 굽힘 강성을 얻을 수 있다.Formed in the form of air sacs of Example 2, the wing 10, the gas is injected therein pressure

There is a force and restoring force to maintain the circularity is applied, the tensile force on the wing 10 is injected gas

When added, the bending stiffness is increased to obtain the same bending stiffness with a smaller tensile force than the blade 10 of the first embodiment.

Since the mathematical derivation and result formula for the actual wing shape is very complex, the following results can be obtained for the simple cylindrical vessel (Cylindrical vessel).

, 두께가

인 원기둥에 내부 압력

가 작용할 경우 세로 방향으로의 응력(longitudinal stress)

은 [수학식 4]와 같이 주어진다.Radius

, Thick

Internal pressure on the cylinder

Longitudinal stress when

Is given by Equation 4.

&Quot; (4) "

에 두께

를 곱하면 내부 압력으로 인한 단위 길이당 인장력

가 된다. 실시 예1에서의 판의 경우와 식은 다르지만 동일한 원리로 인장력

에 의해 굽힘 강성이 증대되며, 상기 날개에 인장력

가 함께 가해지면 굽힘 강성이 더 증대될 수 있다. Stress in the longitudinal direction

On thickness

Multiply by the tensile force per unit length due to internal pressure

Becomes Tensile force on the same principle but different from the case of the plate in Example 1

Bending rigidity is increased by the tensile force on the blade

When applied together, the bending stiffness can be further increased.

The above calculations hold only for isotropic elastomers, but the principles are the same for non-linear solids. Therefore, by applying an appropriate tensile force to the wing is injected gas, the bending rigidity can be increased, the deformation of the wing can be reduced, and thus a thin film-type wing can be used as a lift wing.

Example 3

Embodiment 3 of the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle wing (b) by adjusting the angle of the rudder 40 by the force applied to the rudder 40 from the surrounding flow to the wing 10 Adjusting the direction of the force to act as a tensioning force, and (a) tensioning the blade (10) by the tension generating portion (20) by applying a force outwardly in the longitudinal direction of the blade (10); Or (c) injecting gas into an inner space of the wing 10 formed in the form of an air sac; It includes.

Referring to Figures 5 to 6, Example 3 is applied to the rudder 40 from the surrounding flow by adjusting the angle of the rudder 40 that may be provided in the tensile force generating section 20 or the auxiliary wing 30 The direction of the force is adjusted so that the losing force acts as a force for tensioning the blade 10.

The method of increasing the bending stiffness through the tension of the wing of the unmanned aerial vehicle of the third embodiment is such that the flying fuselage used as the tension generating unit 20 has an airfoil cross section in the longitudinal direction instead of a general cylindrical shape. In addition, the force applied to the rudder 40 from the surrounding flow by adjusting the angle by receiving a force in a direction for tensioning the blade 10 or by installing a steering blade surface such as the rudder 40 is applied to the wing 10. It is to control the direction of the force to act as a tensioning force.

As described above, the method of increasing the bending rigidity of the blade 10 using the rudder 40 is applicable to both the first and second embodiments, in addition to the tensile force generating unit 20 or the auxiliary wing 30. It is also possible to install the rudder 40, by using the existing rudder 40 to adjust the angle of the rudder 40 in accordance with the need of the tensile force to act as a tensile force to the force applied to the rudder 40 from the surrounding flow. can do.

The rudder 40 is preferably provided at each of the tensile force generating units 20 provided at both ends of the wing 10 and controlled at the same time. Two rudders 40 are angled in opposite directions, respectively, from the surrounding flow. Preferably, the force applied can be applied in the direction of tensioning the blade (10).

5 is a schematic diagram of Embodiment 3, wherein the initial position of the rudder 40 is indicated by a dotted line, and the position of the rudder 40 when the force applied to the rudder 40 from the surrounding flow is used as the tensile force is represented by a solid line. Indicated.

The method of increasing the bending stiffness of the unmanned aerial vehicle wing of Embodiment 3 is such that the force applied from the flow around the unmanned aerial vehicle can be applied in the direction of tensioning the wing 10 by the rudder 40. It can be applied to the first and the second embodiment to allow the force to tension the wing 10 can be further increased.

In addition, the unmanned aerial vehicle 1 varies in magnitude of bending stiffness required according to changes in the surrounding environment, such as gusts and turbulence, and lift and drag applied to the wings 10, by adjusting the angle of the rudder 40. By utilizing the force applied from the flow as the tensile force it is possible to increase the bending rigidity of the blade (10).

Accordingly, the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wing of the present invention by actively controlling the bending stiffness of the wing through the additional thrust to tension the wing of the unmanned aerial vehicle on both sides of the structural material There is an advantage that the lifting force required for the unmanned aerial vehicle can be generated while preventing stalling and breakage due to local turbulence without reinforcing the structure through additional use.

In addition, the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wings of the present invention by actively controlling the bending stiffness through the tensile force of the thin film wings and by controlling the shape to generate lift, It is possible to reduce the weight and increase the wing area without a sudden increase in weight, and thus has the advantage of maintaining sufficient lift even at high altitudes.

In addition, the method of increasing the bending stiffness through the tension of the unmanned aerial vehicle and the unmanned aerial vehicle wing of the present invention, because the wing is made of a thin film can increase the area of the wing without reinforcing the structure, so that the solar cell is mounted on the wing solar energy It is suitable for an unmanned aerial vehicle using energy as an energy source, and there is an advantage that the unmanned aerial vehicle using solar energy can be applied to allow long-term flight at high altitude.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It goes without saying that various modifications can be made.

1: unmanned aerial vehicle
10: wing
20: tensile force generating unit
30: auxiliary wing
40: Rudder

Claims (10)

In the unmanned aerial vehicle 1 provided with a wing 10,
The unmanned aerial vehicle 1
Unmanned aircraft, characterized in that it comprises a tensile force generating portion 20 which is provided at both ends in the longitudinal direction of the wing (10) to tension the wing (10) in the longitudinal direction.
The method of claim 1,
The wing 10 of the unmanned aerial vehicle 1
Unmanned aerial vehicle comprising a membrane.
The method of claim 2,
The wing 10 is
Unmanned aerial vehicle characterized in that the fabric is made of synthetic resin or air impermeable to prevent permanent deformation and breakdown due to bending stress applied during flight.
The method according to any one of claims 2 to 3,
The unmanned aerial vehicle 1
At least one of the auxiliary blade 30 and a propeller for generating a tensile force in the direction in which the wing 10 is tensioned is provided on the other side opposite to one side of the tension force generation unit 20 to which the wing 10 is connected. Unmanned aerial vehicle, characterized in that.
The method of claim 4, wherein
The unmanned aerial vehicle 1
Unmanned aerial vehicle further comprises a rudder (40) in the tensile force generating unit 20 or the auxiliary wing (30) to utilize the force received from the surrounding flow as a tensile force.
The method of claim 5
The tensile force generation unit 20
Unmanned aerial vehicle characterized in that the cross section in the longitudinal direction is a wing-shaped flying fuselage so that the tensile force generating unit 20 receives the force in the direction of generating the tensile force continuously.
The method of claim 6,
The wing 10 is
Unmanned aerial vehicle characterized in that it is formed in the form of air sacs to be injected.
In the method of increasing the bending rigidity of the unmanned aerial vehicle wing by tensioning the wing 10 of the unmanned aerial vehicle 1 according to any one of claims 1 to 7,
(A) the tensile force generating portion 20 is a bending stiffness through the tension of the unmanned aerial vehicle wing comprising the step of tensioning the wing 10 by applying a force outward in the longitudinal direction of the wing (10) How to increase.
The method of claim 8,
Method of increasing the bending rigidity through the tension of the unmanned aerial vehicle wing
(b) adjusting the direction of the force such that the force applied to the rudder 40 from the surrounding flow acts as a force to tension the blade 10 by adjusting the angle of the rudder 40. Method of increasing the bending rigidity through the tension of the wing of the drone.
The method according to claim 8 or 9,
Method of increasing the bending rigidity through the tension of the unmanned aerial vehicle wing
(C) a method of increasing the bending rigidity through the tension of the wing of the unmanned aerial vehicle comprising the step of injecting gas into the inner space of the wing (10) formed in the form of air sacs.

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