WO2014108459A1

WO2014108459A1 - Aerodynamic multicopter / quadrocopter

Info

Publication number: WO2014108459A1
Application number: PCT/EP2014/050280
Authority: WO
Inventors: Daniel Schübeler; Sven Jürss
Original assignee: microdrones GmbH
Priority date: 2013-01-09
Filing date: 2014-01-09
Publication date: 2014-07-17
Also published as: DE102013000168A1; DE102013000168B4

Abstract

The invention relates to a drone (1) comprising at least four rotors (2, 3, 4, 5) and an aerodynamically shaped fuselage (6), wherein at least two rotors (2, 3) are arranged along a longitudinal axis of the fuselage (6) and at least two rotors (4, 5) are arranged along a transverse axis of the fuselage (6), wherein the rotor (2) that is installed along the longitudinal axis in the direction of flight is provided at a first distance from the fuselage (6) along a vertical axis, the rotors (4, 5) along the transverse axis are provided at a second distance from the fuselage (6) along a vertical axis, and the rotor (3) that is installed along the longitudinal axis counter to the direction of flight is provided at a third distance from the fuselage (6) along a vertical axis. In particular, the rotors (2, 3, 4, 5) are arranged in a plane which is inclined relative to the vertical axis and in decreasing height from front to rear as viewed in the direction of flight.

Description

The invention relates to a drone comprising at least four rotors and an aerodynamically shaped fuselage, wherein the at least four rotors are arranged symmetrically to the fuselage and at least two rotors along a longitudinal axis of the fuselage and at least two rotors along a transverse axis of the fuselage. Drones or unmanned aerial vehicles are usually equipped with optical recording devices or measuring sensors and used for monitoring. This is the case when the use of manned aircraft is either too expensive or too dangerous for a pilot.

The areas of application are, for example, surveillance in agriculture, the taking of aerial photos for cartography, military reconnaissance, police and emergency operations as well as the supervision of major construction projects and the education in disaster areas. Frequently while the drone is provided with a recording device, such as a camera. The recordings are then transmitted to a base station for further processing of the image and telemetry data. This is particularly advantageous in large-scale applications, wherein the recording and evaluation can be automated, such as in the monitoring of large acreage in agriculture or shooting for mapping. Furthermore, equipped with measuring instruments drones in a disaster area, for example, determine the pollution of the air with pollutants. When assessing damage, drones can be used efficiently. The drone overflies at a low altitude to a point of damage and thus can provide an overview of the damage or the impact of the air.

The use of drones requires a wide variety of flight phases such as takeoff, landing, hovering, slow level flight, fast level flight and their transitions. This results in high demands on the flight characteristics of the drone.

In the prior art, this can be found different designs of drones, for example, as wing aircraft or rotorcraft. Aircraft are suitable for the very fast overflight of large areas, but are limited by the requirements of runways, and a minimum flight speed to ensure the necessary buoyancy, especially for local operations only partially operational.

Rotorcraft such as helicopters impose only minimal conditions on take-off and landing positions and enable close-up shots, especially in slow horizontal flight or in a hover phase. Rotorcraft have rotors to produce the necessary buoyancy. The energy required to generate the lift with the help of a rotor compared to wings of an aircraft is relatively large. As a result, the range and duration of use of rotary wing aircraft is very limited.

In addition, electric motors are increasingly being used in drones, as these are light and quiet compared to internal combustion engines. To drive the electric motors batteries must be carried. The energy density of the entrained batteries is, however, significantly lower than the energy density of fossil fuel for internal combustion engines. Thus, the range and the duration of use of rotary wing aircraft with electric motors is further limited. Frequently used as drones quadrocopter or four-winged. These have four vertically downward rotors or propellers, arranged in a flat plane with respect to the vertical axis of the drone, to provide propulsion and propulsion by tilting the rotor plane. Furthermore, allow the four rotors in a plane, for example, solely by changing the speed control over the axes of the fuselage.

Conventional rotorcraft such as helicopters have a rotor and a tail rotor to compensate for the torque caused thereby. Since the tail rotor makes no contribution to the buoyancy or propulsion of the helicopter, the energy saving of the drone is increased by saving the tail rotor in a quadrocopter.

To further increase the range and duration of the drone, the drone's fuselage can be aerodynamically trained. This reduces air resistance and requires less energy during horizontal flight. In addition, dynamic buoyancy can be generated.

However, the prior art solutions for increasing energy efficiency are not sufficient to meet the range and duration requirements of the drone for applications such as agriculture, cartography, military reconnaissance, police and emergency operations, and monitoring of drones To ensure large-scale construction projects and education in disaster areas.

Therefore, the task is to further increase the energy efficiency and thus the range and duration of use of drones.

The invention achieves this object by providing the rotor mounted in the direction of flight along the longitudinal axis at a first distance, the rotors along the transverse axis at a second distance and the rotor mounted along the longitudinal axis against the direction of flight at a third distance from the fuselage along a vertical axis are. The drone is designed, for example, as a quadrocopter or four-wing, multicopter, or polycopter. In this case, a particular advantage of the invention over the prior art is that the rotor mounted along the longitudinal axis in the direction of flight at a first distance, the rotors along the transverse axis at a second distance and along the longitudinal axis against the direction of flight mounted rotor at a third distance are arranged to the hull along a vertical axis. The distances can be different. Due to the different distances between the rotors and the fuselage, the drone takes on a particularly aerodynamic shape during horizontal or forward flight. The rotors can be designed, for example, as engines.

The rotors of the drone according to the invention are, in other words, arranged in the direction of flight from front to rear in descending height relative to a vertical plane perpendicular to the vertical axis of the drone. In horizontal flight, the drone tilts in the direction of flight and the rotors are then arranged in a horizontal plane. In contrast, in the prior art, the rotors are arranged with respect to the vertical axis of the drone in a horizontal plane.

In an advantageous embodiment of the invention, the hull is provided below the at least four rotors. This is particularly advantageous when using the drone for monitoring, wherein the hull receives, for example, an optical recording device. The recording device is typically mounted below the fuselage. Since the hull itself is provided below the rotors, the recordings are not affected by the rotors and it ensures a high quality. Furthermore, the arrangement of the center of gravity below the rotors ensures good flight stability.

In a further advantageous embodiment of the invention, the hull is provided above the at least four rotors. This is particularly advantageous when using the drone with gauges, such as for measuring air pollution. The measuring devices are arranged as far as possible outside the air turbulence generated by the rotors. In a further particularly advantageous embodiment of the invention, the hull is provided within the plane spanned by the rotors. This results in a good energy efficiency, since the volume and drag of the drone are minimized. A further embodiment of the invention provides that the hull is aerodynamically shaped such that the cross section of the hull along the longitudinal axis is formed as a wing profile. The airfoil profile generates additional buoyancy, especially during level flight. This increases the energy efficiency of the drone. The shape of the airfoil serves on the one hand to achieve as much buoyancy with the least possible flow resistance, and on the other hand to allow the largest possible Anstellwinkelbereich without stall. Depending on the design, different wing profiles can be used. In a further advantageous embodiment, the hull on a landing device. This is required for the drone to take off safely and land safely. In this case, the landing device is designed, for example, as landing skids, landing gear with wheels, landing skis or water skips with floating elements. Landing skids thereby comprise two holding tubes, which are mounted transversely to the fuselage, and two further longitudinal tubes. Due to their simple construction, landing skids are easy to manufacture and maintenance-free. Furthermore, landing skids weigh less and offer less air resistance than other embodiments of the landing gear.

Another embodiment provides that a fastening cross is formed from two struts and one strut each connects the hull with at least two rotors. The fixing cross ensures a stable and secure connection between the fuselage and the rotors.

In an advantageous embodiment, at least the transverse to the forward flight direction struts of the attachment cross are flat. The struts cause no additional air turbulence, and the air resistance of the struts is as small as possible. In a further advantageous embodiment, the struts of the fastening cross are aerodynamically shaped along the transverse axis of the fuselage in such a way that the cross section of the struts along the longitudinal axis is formed as a wing profile. The airfoil profile generates additional buoyancy, especially during level flight. This will further increase the energy efficiency of the drone.

Further features, details and advantages of the invention will become apparent from the wording of the claims and from the description of exemplary embodiments with reference to FIGS. The invention will be explained in more detail with reference to the following text with reference to preferred embodiments with reference to the figures.

It shows

Fig. 1: in a perspective view a

Drone with four rotors and a hull, and

2 shows a side view of a drone with four

Rotors at different distances.

The reference numerals and their meaning are summarized in the list of reference numerals. In general, the same reference numerals designate the same parts.

FIG. 1 shows a perspective view of a drone 1 with four rotors 2, 3, 4, 5 and a fuselage 6. The rotor 2 mounted along the longitudinal axis in the direction of flight is at a first distance, the rotors 4, 5 along the transverse axis in FIG a second distance and the rotor 3 mounted along the longitudinal axis against the direction of flight provided at a third distance from the fuselage 6. In the illustrated embodiment, all three distances are different. The illustrated drone 6 is a quadrocopter or four-wing. The drone 6 may be formed in other versions as a multicopter or a polycopter with more than four rotors. In the Quadrokopterbauweise the rotors 2, 3, 4, 5 are driven for example by electric motors. The electrical energy for the electric motors is typically provided by batteries, such as lithium-polymer batteries.

In quadrocopter design, unlike helicopters, no mechanical components, such as helicopters, are used for control. Swashplates, variable pitch propeller or rudder needed. The rotors 2, 3, 4, 5 are fixedly mounted on a motor, such as an electric motor or connected via a transmission with this. Changes in lift are made solely by increasing or decreasing the engine speed. If the speed of all engines is increased or decreased at the same time, the drone 1 rises or falls.

In the case of the drone 1 designed as a quadrocopter, two of the rotors 2, 3, 4, 5 rotate in each case and the two other rotors in the counterclockwise direction. As a result, the torques, which are transmitted from the rotors 2, 3, 4, 5 to the hull, cancel out accordingly.

Rotations about the longitudinal or transverse axis of the drone 1 are effected by different control of the rotors 2, 3, 4, 5 lying on the respective axis. The rotational speed of the left- or right-handed rotors 2, 3, 4, inversely proportional to so that the sum of the torques generated by them remains the same.

The drone 1 is further provided with a landing device 7. In the illustrated embodiment, the landing device 7 is designed as landing skids. Furthermore, depending on the area of use, rolls, Landeski or water skates with floating elements can be used. The landing skids are particularly simple and comprise four holding tubes 10, which are mounted transversely to the fuselage, and two longitudinal tubes 1 1, which form runners. A designed as land skids landing device 7 weighs less and offers less air resistance than, for example, a solid wheels suspension. In addition, skids reduce in comparison to other embodiments the risk of being attached to objects on the ground such as. To catch shrubs or the like.

The rotors 2, 3, 4, 5 are mounted on a fastening cross, which is formed from two struts 8, 9, fixed. The struts 8, 9 in each case run along the longitudinal axis and the transverse axis. The hull 6 of the drone 1 takes on the mounting cross, wherein the struts 8, 9 the hull 6 fixed to the rotors 2, 3, 4, 5 connect. The conclusion of the struts 8, 9 with the hull 6 is provided with a closing the hull approach surface 12.

The hull 6 is further provided with a fastening device 13 on the upper and lower part. The fastening device 13 serves for attachment of recording or measuring devices. In this case, an optical recording device is preferably attached to the lower part of the fuselage 6 and measuring devices preferably further away from the fuselage. Thus, high-quality optical recordings or measurement data can be recorded. Furthermore, the hull 6 can be provided with a transmitting device for the wireless transmission of data of the recording device or of the measuring devices. Thus, the data can be sent immediately after recording for further processing, for example, to a ground station.

Figure 2 shows a side view of the drone with four rotors 2, 3, 4, 5 at different distances from the fuselage. In horizontal flight, the drone 1 tends in the direction of flight. As a result, the relative position of the rotor 2 mounted along the longitudinal axis in the direction of flight decreases with respect to the fuselage 6, while the rotor 3 mounted along the longitudinal axis against the direction of flight increases relative to the fuselage 6. The rotors 2, 3, 4, 5 are arranged in a plane inclined with respect to the vertical axis and in the direction of flight from front to rear in decreasing distance. This results in a particularly advantageous aerodynamic shape of the drone. 1 The rotor 2 is mounted in the direction of flight such that it lies in horizontal flight on a line with the hull 6. The rotor 5 is provided such that it is also in a horizontal flight on a line with the hull 6. This results in comparison to the prior art a reduced attack surface, with which the air resistance of the drone decreases accordingly. Thus, in horizontal flight less energy for the propulsion must be expended, and the range or duration of use of the drone 1 is increased accordingly. In further embodiments, the hull 6 of the drone 1 can also be above or below the plane spanned by the rotors 2, 3, 4, 5. This ensures an advantageous attachment of recording devices or measuring devices. An optical recording device is typically mounted below the fuselage. The hull 6 itself is provided below the rotors 2, 3, 4, 5 in order not to impair the recordings by the rotors 2, 3, 4, 5 and to ensure a high quality. Measuring devices are preferably mounted farther away from the fuselage. As a result, air turbulences are avoided by the rotors 2, 3, 4, 5 in the field of measuring devices and prevents errors in the measurement. In the illustrated embodiment of the drone 1, the fuselage 6 is aerodynamically shaped such that the cross section of the fuselage 6 along the longitudinal axis is formed as a wing profile. The wing profile generates a buoyancy during horizontal flight. The shape of the airfoil serves on the one hand to achieve as much buoyancy with the least possible flow resistance, and on the other hand to allow the largest possible Anstellwinkelbereich without stall. In forward flight, due to the inclination of the drone 1, the fuselage 6 receives the optimum angle of attack to maximize lift and minimize aerodynamic drag.

- List of Reference Signs -

LIST OF REFERENCES

I drone

2 rotor

3 rotor

4 rotor

5 rotor

6 hull

7 landing gear

8 strut

9 strut

10 holding tube

I I pipe

12 approach surface

13 fastening device

- Claims -

Claims

claims

1 . Drone (1) comprising at least four rotors (2, 3, 4, 5) and an aerodynamically shaped hull (6), wherein the at least four rotors (2, 3, 4, 5) symmetrical to the hull (6) and at least two rotors (2, 3) are arranged along a longitudinal axis of the fuselage (6) and at least two rotors (4, 5) along a transverse axis of the fuselage (6), characterized in that the rotor (2) mounted along the longitudinal axis in the direction of flight in a first Distance, the rotors (4, 5) along the transverse axis at a second distance and along the longitudinal axis against the flight direction mounted rotor (3) are provided at a third distance from the fuselage (6) along a vertical axis.

2. drone (1) according to claim 1, wherein the rotors (2, 3, 4, 5) are arranged in a plane inclined with respect to the vertical axis and in the direction of flight from front to rear in descending height.

3. drone (1) according to one of claims 1 or 2, wherein the hull (6) above or below the at least four rotors (2, 3, 4, 5) or within of the rotors (2, 3, 4, 5 ) spanned level is provided.

4. drone (1) according to any one of claims 1, 2 or 3, wherein the hull (6) is aerodynamically shaped such that the cross section of the hull

(6) is formed along the longitudinal axis as a wing profile.

5. drone (1) according to one of claims 1 to 4, wherein the hull (6) has a landing device (7).

6. drone (1) according to one of claims 1 to 5, wherein a fixing cross of two struts (8, 9) is formed and in each case a strut (8, 9) the hull (6) with at least two rotors (2, 3, 4, 5) connects.

7. drone (1) according to claim 6, wherein the struts (8, 9) of the fastening cross are formed flat.

8. drone (1) according to claim 6, wherein the struts (8, 9) of the fastening cross along the transverse axis of the fuselage (6) are aerodynamically shaped in such a way that the cross section of the struts (8, 9) along the longitudinal axis as a Wing profile is formed

- Summary -